Problem:
ブロックの三角形
図a のように積まれたブロックに対し、以下の並べ替え操作を繰り返す。
一番下のブロック全て（図a 中の白のブロック）を右端に新しく積み上げる（残りのブロックは自動的に１段下に落ち、図b のようになる）。
ブロックの間に隙間ができたら、左に詰めて隙間をなくす（図 b から図c のようになる）。
1 以上の整数 k に対して、k×(k＋1)/2 で表される数 (例:1, 3, 6, 10, ...)を三角数という。ブロックの総数が三角数の場合、上記の並べ替えを繰り返すと、左端の高さが1 で右に向かって１つずつ高くなっていくような三角形になると予想されている（図d は総数が15 個の場合）。
ブロックの最初の並びが与えられたとき、あらかじめ決められた回数以下の操作で、上で説明したようなブロックの三角形ができるとき、三角形が得られるまでの最小の操作回数を出力するプログラムを作成してください。
入力
入力は複数のデータセットからなる。入力の終わりはゼロ１つの行で示される。各データセットは以下の形式で与えられる。
N
b
1
b
2
... b
N
各データセットは２行であり、ブロックの最初の並びを表す。N (1 ≤ N ≤ 100)は、一番下の段にあるブロックの数を示す。b
i
(1 ≤ bi ≤ 10000) は左から i 番目の位置に積まれているブロックの数を示す。b
i
と b
i+1
は１つの空白で区切られている。ブロックの総数は 3 以上である。
データセットの数は 20 を超えない。
出力
データセットごとに、三角形ができるまでに行った並べ替え操作の回数を１行に出力する。ただし、三角形が作れない場合や、操作回数が 10000 回を超える場合は -1 を出力する。
入力例
6
1 4 1 3 2 4
5
1 2 3 4 5
10
1 1 1 1 1 1 1 1 1 1
9
1 1 1 1 1 1 1 1 1
12
1 4 1 3 2 4 3 3 2 1 2 2
1
5050
3
10000 10000 100
0
出力例
24
0
10
-1
48
5049
-1
最初のデータセットが、図に示した場合に対応する。
４つ目のデータセットが、ブロックの総数が三角数でないため、三角形が作れない場合に対応する。
最後のデータセットが、ブロックの総数は三角数だが、操作回数が 10000 回を超える場合に対応する。

Submitted solutions:

code_snippet: #include <iostream>
#include <vector>
using namespace std;

const int MAX_CNT = 10000;
const int MAX_SET = 20;

int main()
{
    int N;
    int setcount = 0;


    while (cin >> N && N != 0 && setcount < MAX_SET)
    {
        if (N < 1 || 1000 < N)
        {
            cout << "N(1 <= N <= 100) " << endl << flush;
            exit(1);
        }
        vector<int> b;
        for (int i = 0; i < N; i++)
        {
            int v;
            cin >> v;
            if (v < 1 || 10000 < v)
            {
                cout << "b" << i << "(1 <= bi <= 10000) but input" << v << endl << flush;
                exit(1);
            }
            b.push_back(v);
        }
        int cnt = 0;
        while (cnt <= MAX_CNT)
        {
            bool isTriangle = true;
            if (b[0] != 1)
            {
                isTriangle = false;
            }
            else
            {
                for (int i = 1; i < b.size(); i++)
                {
                    if (b[i] != b[i - 1] + 1)
                    {
                        isTriangle = false;
                        break;
                    }
                }
            }
            if (isTriangle) break;
            vector<int> work;
            for (int num:b)
            {
                if (num >1)
                {
                    work.push_back(num - 1);
                }
            }
            work.push_back(b.size());
            b = work;

            cnt++;
        }
        if (cnt > MAX_CNT)
        {
            cout << -1 << endl << flush;
        }
        else
        {
            cout << cnt << endl << flush;
        }
        setcount++;
    }
}
accuracy: 1
time_ms: 100
memory_kb: 3456
final_rank: 11

code_snippet: #line 1 "/opt/library/template.hpp"
#include <bits/stdc++.h>
using namespace std;

using ll = long long;
using i64 = long long;
using u32 = unsigned int;
using u64 = unsigned long long;
using i128 = __int128;
using u128 = unsigned __int128;
using f128 = __float128;

template <class T>
constexpr T infty = 0;
template <>
constexpr int infty<int> = 1'000'001'000;
template <>
constexpr ll infty<ll> = ll(infty<int>) * infty<int> * 2;
template <>
constexpr u32 infty<u32> = infty<int>;
template <>
constexpr u64 infty<u64> = infty<ll>;
template <>
constexpr i128 infty<i128> = i128(infty<ll>) * infty<ll>;
template <>
constexpr double infty<double> = infty<ll>;
template <>
constexpr long double infty<long double> = infty<ll>;
#define inf infty<ll>

using pi = pair<ll, ll>;
using vi = vector<ll>;
using vvi = vector<vector<ll>>;
template <class T>
using vc = vector<T>;
template <class T>
using vvc = vector<vc<T>>;
template <class T>
using vvvc = vector<vvc<T>>;
template <class T>
using vvvvc = vector<vvvc<T>>;
template <class T>
using vvvvvc = vector<vvvvc<T>>;
template <class T>
using pq = priority_queue<T>;
template <class T>
using pqg = priority_queue<T, vector<T>, greater<T>>;

#define vv(type, name, h, ...) \
  vector<vector<type>> name(h, vector<type>(__VA_ARGS__))
#define vvv(type, name, h, w, ...)   \
  vector<vector<vector<type>>> name( \
      h, vector<vector<type>>(w, vector<type>(__VA_ARGS__)))
#define vvvv(type, name, a, b, c, ...)       \
  vector<vector<vector<vector<type>>>> name( \
      a, vector<vector<vector<type>>>(       \
             b, vector<vector<type>>(c, vector<type>(__VA_ARGS__))))

#define rep1(a) for (ll _ = 0; _ < (ll)(a); ++_)
#define rep2(i, a) for (ll i = 0; i < (ll)(a); ++i)
#define rep3(i, a, b) for (ll i = a; i < (ll)(b); ++i)
#define rep4(i, a, b, c) for (ll i = a; i < (ll)(b); i += (c))
#define rrep1(a) for (ll i = (a)-1; i >= (ll)(0); --i)
#define rrep2(i, a) for (ll i = (a)-1; i >= (ll)(0); --i)
#define rrep3(i, a, b) for (ll i = (b)-1; i >= (ll)(a); --i)
#define rrep4(i, a, b, c) for (ll i = (b)-1; i >= (ll)(a); i -= (c))
#define overload4(a, b, c, d, e, ...) e
#define rep(...) overload4(__VA_ARGS__, rep4, rep3, rep2, rep1)(__VA_ARGS__)
#define rrep(...) overload4(__VA_ARGS__, rrep4, rrep3, rrep2, rrep1)(__VA_ARGS__)

#define all(x) (x).begin(),(x).end()
#define len(x) (ll)(x.size())
#define elif else if
#define bit(x, i) (((x)>>(i))&1)

#define eb emplace_back
#define mp make_pair
#define mt make_tuple
#define fi first
#define se second

#define stoi stoll
#define abs llabs

#define MIN(v) *min_element(all(v))
#define MAX(v) *max_element(all(v))
#define LB(c, x) distance((c).begin(), lower_bound(all(c), (x)))
#define UB(c, x) distance((c).begin(), upper_bound(all(c), (x)))
#define UNIQUE(x) \
  sort(all(x)), x.erase(unique(all(x)), x.end()), x.shrink_to_fit()

ll popcnt(ll x) { return __builtin_popcountll(x); }
ll popcnt(u64 x) { return __builtin_popcountll(x); }
ll popcnt_mod_2(ll x) { return __builtin_parityll(x); }
ll popcnt_mod_2(u64 x) { return __builtin_parityll(x); }
ll topbit(ll x) { return (x == 0 ? -1 : 63 - __builtin_clzll(x)); }
ll topbit(u64 x) { return (x == 0 ? -1 : 63 - __builtin_clzll(x)); }
ll lowbit(ll x) { return (x == 0 ? -1 : __builtin_ctzll(x)); }
ll lowbit(u64 x) { return (x == 0 ? -1 : __builtin_ctzll(x)); }

template <typename T>
T floor(T a, T b) {
  return a / b - (a % b && (a ^ b) < 0);
}
template <typename T>
T ceil(T x, T y) {
  return floor(x + y - 1, y);
}
template <typename T>
T bmod(T x, T y) {
  return x - y * floor(x, y);
}
template <typename T>
pair<T, T> divmod(T x, T y) {
  T q = floor(x, y);
  return {q, x - q * y};
}

template<typename T> T SUM(const vector<T> &A) {
  T s = 0; for (auto &&a: A) s += a;
  return s;
}

template <typename T>
T POP(queue<T> &que) {
  T a = que.front();
  que.pop();
  return a;
}
template <typename T>
T POP(deque<T> &que) {
  T a = que.front();
  que.pop_front();
  return a;
}
template <typename T>
T POP(pq<T> &que) {
  T a = que.top();
  que.pop();
  return a;
}
template <typename T>
T POP(pqg<T> &que) {
  T a = que.top();
  que.pop();
  return a;
}
template <typename T>
T POP(vc<T> &que) {
  T a = que.back();
  que.pop_back();
  return a;
}

template <typename F>
ll binary_search(F check, ll ok, ll ng, bool check_ok = true) {
  if (check_ok) assert(check(ok));
  while (abs(ok - ng) > 1) {
    auto x = (ng + ok) / 2;
    (check(x) ? ok : ng) = x;
  }
  return ok;
}
template <typename F>
f128 binary_search_real(F check, f128 ok, f128 ng, ll iter = 100) {
  rep(iter) {
    f128 x = (ok + ng) / 2;
    (check(x) ? ok : ng) = x;
  }
  return (ok + ng) / 2;
}

// ? は -1
vc<int> s_to_vi(const string &S, char first_char) {
  vc<int> A(S.size());
  rep(i, S.size()) { A[i] = (S[i] != '?' ? S[i] - first_char : -1); }
  return A;
}

template <typename T, typename U>
vc<T> cumsum(vc<U> &A, ll off = 1) {
  ll N = A.size();
  vc<T> B(N + 1);
  rep(i, N) { B[i + 1] = B[i] + A[i]; }
  if (off == 0) B.erase(B.begin());
  return B;
}

// stable sort
template <typename T>
vi argsort(const vector<T> &A) {
  vi ids(len(A));
  iota(all(ids), 0);
  sort(all(ids),
       [&](ll i, ll j) { return (A[i] == A[j] ? i < j : A[i] < A[j]); });
  return ids;
}

// A[I[0]], A[I[1]], ...
template <typename T>
vc<T> rearrange(const vc<T> &A, const vi &I) {
  vc<T> B(len(I));
  rep(i, len(I)) B[i] = A[I[i]];
  return B;
}

template<typename T> inline bool chmax(T &a, T b) {return ((a<b)?(a=b,true):(false));}
template<typename T> inline bool chmin(T &a, T b) {return ((a>b)?(a=b,true):(false));}

inline void wt(const char c) { cout << c; }
inline void wt(const string s) { cout << s; }
inline void wt(const char *s) { cout << s; }

template <typename T>
void wt_integer(T x) {
  cout << (x);
}
template <typename T>
void wt_real(T x) {
  cout << fixed << setprecision(15) << (long double)(x);
}
template <typename T>
void wt_integer128(T x) {
  char buf[64];
  char *d = end(buf);
  d--; *d = '\0';
  __uint128_t tmp = ((x < 0)? -x : x);
  do {
    d--; *d = char(tmp%10 + '0'); tmp /= 10;
  } while (tmp);
  if (x < 0) {
    d--; *d = '-';
  }
  cout << d;
}

inline void wt(int x) { wt_integer(x); }
inline void wt(ll x) { wt_integer(x); }
inline void wt(i128 x) { wt_integer128(x); }
inline void wt(u32 x) { wt_integer(x); }
inline void wt(u64 x) { wt_integer(x); }
inline void wt(u128 x) { wt_integer128(x); }
inline void wt(double x) { wt_real(x); }
inline void wt(long double x) { wt_real(x); }
inline void wt(f128 x) { wt_real(x); }

template <class T, class U>
void wt(const pair<T, U> val) {
  wt(val.first); wt(' '); wt(val.second);
}
template <size_t N = 0, typename T>
void wt_tuple(const T t) {
  if constexpr (N < std::tuple_size<T>::value) {
    if constexpr (N > 0) { wt(' '); }
    const auto x = std::get<N>(t);
    wt(x);
    wt_tuple<N + 1>(t);
  }
}
template <class... T>
void wt(tuple<T...> tpl) {
  wt_tuple(tpl);
}
template <class T, size_t S>
void wt(const array<T, S> val) {
  auto n = val.size();
  for (size_t i = 0; i < n; i++) {
    if (i) wt(' ');
    wt(val[i]);
  }
}
template <class T>
void wt(const vector<T> val) {
  auto n = val.size();
  for (size_t i = 0; i < n; i++) {
    if (i) wt(' ');
    wt(val[i]);
  }
}

void print() { wt('\n'); }
template <class Head, class... Tail>
void print(Head &&head, Tail &&... tail) {
  wt(head);
  if (sizeof...(Tail)) wt(' ');
  print(forward<Tail>(tail)...);
}

void YES(bool t = 1) { print(t ? "YES" : "NO"); }
void NO(bool t = 1) { YES(!t); }
void Yes(bool t = 1) { print(t ? "Yes" : "No"); }
void No(bool t = 1) { Yes(!t); }
void yes(bool t = 1) { print(t ? "yes" : "no"); }
void no(bool t = 1) { yes(!t); }
void onez(bool t = 1) { print(t ? 1 : 0); }
#define endl '\n'
#define dump(x) {cerr << #x " = " << x << '\n';}
#line 2 "main.cpp"

int solve();
int main() {
  cin.tie(nullptr);
  ios_base::sync_with_stdio(false);
  while (!solve()) {}
  return 0;
}

int solve() {
  ll N;
  cin >> N;
  if (N == 0) return 1;
  vi b(N);
  rep(i, N) cin >> b[i];
  ll sum = SUM(b);
  ll x = ll(sqrt(sum*2) + 1e-9);
  if (x*(x+1) != sum*2) {
    print(-1);
    return 0;
  }
  vi t(b);
  rep(num, 10001) {
    ll h = 1;
    ll cnt = 0;
    rep(i, len(t)) {
      if (t[i] != h) break;
      h++;
      cnt += t[i];
    }
    if (cnt == sum) {
      print(num);
      return 0;
    }
    t.eb(0);
    rep(i, len(t)-1) {
      if (t[i] >= 1) {
        t[i]--;
        t.back()++;
      }
    }
    vi next;
    rep(i, len(t)) {
      if (t[i] >= 1) next.eb(t[i]);
    }
    swap(t, next);
  }
  print(-1);
  return 0;
}
accuracy: 1
time_ms: 150
memory_kb: 3412
final_rank: 15

code_snippet: #pragma region Macros

#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,fma,abm,mmx,avx,avx2")

#include <bits/extc++.h>
// #include <atcoder/all>
// using namespace atcoder;
using namespace std;
using namespace __gnu_pbds;

// #include <boost/multiprecision/cpp_dec_float.hpp>
// #include <boost/multiprecision/cpp_int.hpp>
// namespace mp = boost::multiprecision;
// using Bint = mp::cpp_int;
// using Bdouble = mp::number<mp::cpp_dec_float<256>>;
// Bdouble Beps = 0.00000000000000000000000000000001; // 1e-32
// const bool equals(Bdouble a, Bdouble b) { return mp::fabs(a - b) < Beps; }

#define pb emplace_back
#define int ll
#define endl '\n'
// #define unordered_map<int, int> gp_hash_table<int, int, custom_hash> 

#define sqrt __builtin_sqrtl
#define cbrt __builtin_cbrtl
#define hypot __builtin_hypotl

#define next asdnext
#define prev asdprev

using ll = long long;
using ld = long double;
const ld PI = acosl(-1);
const int INF = 1 << 30;
const ll INFL = 1LL << 61;
// const int MOD = 998244353;
const int MOD = 1000000007;

const ld EPS = 1e-10;
const bool equals(ld a, ld b) { return fabs((a) - (b)) < EPS; }

const vector<int> dx = {0, 1, 0, -1, 1, 1, -1, -1}; // → ↓ ← ↑ ↘ ↙ ↖ ↗
const vector<int> dy = {1, 0, -1, 0, 1, -1, -1, 1};

struct Edge {
    int from, to;
    double cost;
    Edge() : from(-1), to(-1), cost(-1) {}
    Edge(int to, double cost) : to(to), cost(cost) {}
    Edge(int from, int to, double cost) : from(from), to(to), cost(cost) {}
    bool operator ==(const Edge& e) {
        return this->from == e.from && this->to == e.to && this->cost == e.cost;
    }
    bool operator !=(const Edge& e) {
        return this->from != e.from or this->to != e.to or this->cost != e.cost;
    }
};

chrono::system_clock::time_point start;
__attribute__((constructor))
void constructor() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout << fixed << setprecision(10);
    start = chrono::system_clock::now();
}

random_device seed_gen;
mt19937_64 rng(seed_gen());
uniform_int_distribution<int> dist_x(0, 1e9);
struct RNG {
    unsigned Int(unsigned l, unsigned r) {
        return dist_x(rng) % (r - l + 1) + l;
    }
    ld Double() {
        return ld(dist_x(rng)) / 1e9;
    }
} rnd;

using i64 = ll;
// using i64 = uint64_t;
// bit演算, x==0の場合は例外処理した方がよさそう. 区間は [l, r)
i64 lrmask(i64 l, i64 r) { return (1LL << r) - (1LL << l); }
i64 sub_bit(i64 x, i64 l, i64 r) { i64 b = x & ((1LL << r) - (1LL << l)); return b >> l; } // r溢れ可
i64 bit_width(i64 x) { return 64 - __builtin_clzll(x) + (x == 0); }

i64 popcount(i64 x) { return __builtin_popcountll(x); }
i64 popcount(i64 x, i64 l, i64 r) { return __builtin_popcountll(sub_bit(x, l, r)); }
i64 unpopcount(i64 x) { return bit_width(x) - __builtin_popcountll(x); }
i64 unpopcount(i64 x, i64 l, i64 r) { return r - l - __builtin_popcountll(sub_bit(x, l, r)); }
bool is_pow2(i64 x) { return __builtin_popcountll(x) == 1; }

i64 top_bit(i64 x) { return 63 - __builtin_clzll(x);} // 2^kの位 (x > 0)
i64 bot_bit(i64 x) { return __builtin_ctz(x);} // 2^kの位 (x > 0)
// i64 next_bit(i64 x, i64 k) { return 0; }
// i64 prev_bit(i64 x, i64 k) { return 0; }
// i64 kth_bit(i64 x, i64 k) { return 0; }
i64 MSB(i64 x) { if (x == 0) return 0; return 1LL << (63 - __builtin_clzll(x)); } // mask
i64 LSB(i64 x) { return (x & -x); } // mask

i64 countl_zero(i64 x) { return __builtin_clzll(x); }
i64 countl_one(i64 x) {
    i64 ret = 0, k = 63 - __builtin_clzll(x);
    while (k != -1 && (x & (1LL << k))) { k--; ret++; }
    return ret;
}
i64 countr_zero(i64 x) { return __builtin_ctzll(x); } // x==0のとき64が返ることに注意
i64 countr_one(i64 x) { i64 ret = 0; while (x & 1) { x >>= 1; ret++; } return ret; }

i64 floor_log2(i64 x) { if (x == 0) return 0; return 63 - __builtin_clzll(x); }
i64 bit_floor(i64 x) { if (x == 0) return 0; return 1LL << (63 - __builtin_clzll(x)); } // MSBと同じ
i64 ceil_log2(i64 x) { if (x == 0) return 0; return 64 - __builtin_clzll(x - 1); }
i64 bit_ceil(i64 x) { if (x == 0) return 0; return 1LL << (64 - __builtin_clzll(x - 1)); }

i64 rotl(i64 x, i64 k) { // 有効bit内でrotate. オーバーフロー注意
    i64 w = bit_width(x); k %= w;
    return ((x << k) | (x >> (w - k))) & ((1LL << w) - 1);
}
// i64 rotl(i64 x, i64 l, i64 m, i64 r) {}
i64 rotr(i64 x, i64 k) {
    i64 w = bit_width(x); k %= w;
    return ((x >> k) | (x << (w - k))) & ((1LL << w) - 1);
}
// i64 rotr(i64 x, i64 l, i64 m, i64 r) {}
i64 bit_reverse(i64 x) { // 有効bit内で左右反転
    i64 r = 0, w = bit_width(x);
    for (i64 i = 0; i < w; i++) r |= ((x >> i) & 1) << (w - i - 1);
    return r;
}
// i64 bit_reverse(i64 x, i64 l, i64 r) { return 0; }

bool is_palindrome(i64 x) { return x == bit_reverse(x); }
bool is_palindrome(i64 x, i64 l, i64 r) { i64 b = sub_bit(x, l, r); return b == bit_reverse(b); }
i64 concat(i64 a, i64 b) { return (a << bit_width(b)) | b; } // オーバーフロー注意
i64 erase(i64 x, i64 l, i64 r) { return x>>r<<l | x&(1LL<<l - 1); } // [l, r) をカット

i64 hamming(i64 a, i64 b) { return __builtin_popcountll(a ^ b); }
i64 hamming(i64 a, i64 b, i64 l, i64 r) { return __builtin_popcountll(sub_bit(a, l, r) ^ sub_bit(b, l, r)); }
i64 compcount(i64 x) { return (__builtin_popcountll(x ^ (x >> 1)) + (x & 1)) / 2; }
i64 compcount2(i64 x) { return compcount(x & (x >> 1)); } // 長さ2以上の連結成分の個数
i64 adjacount(i64 x) { return __builtin_popcountll(x & (x >> 1)); } // 隣接する1のペアの個数

i64 next_combination(i64 x) {
    i64 t = x | (x - 1); return (t + 1) | (((~t & -~t) - 1) >> (__builtin_ctz(x) + 1));
}


__int128_t POW(__int128_t x, int n) {
    __int128_t ret = 1;
    assert(n >= 0);
    if (x == 1 or n == 0) ret = 1;
    else if (x == -1 && n % 2 == 0) ret = 1; 
    else if (x == -1) ret = -1; 
    else if (n % 2 == 0) {
        assert(x < INFL);
        ret = POW(x * x, n / 2);
    } else {
        assert(x < INFL);
        ret = x * POW(x, n - 1);
    }
    return ret;
}
int per(int x, int y) { // x = qy + r (0 <= r < y) を満たすq
    assert(y != 0);
    if (x >= 0 && y > 0) return x / y;
    if (x >= 0 && y < 0) return x / y - (x % y < 0);
    if (x < 0 && y < 0) return x / y + (x % y < 0);
    return x / y - (x % y < 0); //  (x < 0 && y > 0) 
}
int mod(int x, int y) { // x = qy + r (0 <= r < y) を満たすr
    assert(y != 0);
    if (x >= 0) return x % y;
    __int128_t ret = x % y; // (x < 0)
    ret += (__int128_t)abs(y) * INFL;
    ret %= abs(y);
    return ret;
}
int floor(int x, int y) { // (ld)x / y 以下の最大の整数
    assert(y != 0);
    if (y < 0) x = -x, y = -y;
    return x >= 0 ? x / y : (x + 1) / y - 1;
}
int ceil(int x, int y) { // (ld)x / y 以上の最小の整数
    assert(y != 0);
    if (y < 0) x = -x, y = -y;
    return x > 0 ? (x - 1) / y + 1 : x / y;
}
int round(int x, int y) {
    assert(y != 0);
    return (x * 2 + y) / (y * 2);
}
int round(int x, int y, int k) { // (ld)(x/y)を10^kの位に関して四捨五入
    assert(y != 0); // TODO
    return INF;
}
int round2(int x, int y) { // 五捨五超入 // 未verify
    assert(y != 0);
    if (y < 0) y = -y, x = -x;
    int z = z / y;
    if ((z * 2 + 1) * y <= y * 2) z++;
    return z;
}
// int round(ld x, int k) { // xを10^kの位に関して四捨五入
// }
// int floor(ld x, int k) { // xを10^kの位に関してflooring
// }
// int ceil(ld x, int k) { // xを10^kの位に関してceiling
// }
// int kth(int x, int y, int k) { // x / yの10^kの位の桁
// }
int floor(ld x, ld y) { // 誤差対策TODO
    assert(!equals(y, 0));
    return floor(x / y);
    // floor(x) = ceil(x - 1) という話も
}
int ceil(ld x, ld y) { // 誤差対策TODO // ceil(p/q) = -floor(-(p/q))らしい
    assert(!equals(y, 0));
    return ceil(x / y);
    // ceil(x) = floor(x + 1)
}
int perl(ld x, ld y) { // x = qy + r (0 <= r < y, qは整数) を満たす q
    // 未verify. 誤差対策TODO. EPS外してもいいかも。
    assert(!equals(y, 0));
    if (x >= 0 && y > 0) return floor(x / y)+EPS;
    if (x >= 0 && y < 0) return -floor(x / fabs(y));
    if (x < 0 && y < 0) return floor(x / y) + (x - floor(x/y)*y < -EPS);
    return floor(x / y) - (x - floor(x/y)*y < -EPS); //  (x < 0 && y > 0) 
}
ld modl(ld x, ld y) { // x = qy + r (0 <= r < y, qは整数) を満たす r
    // 未verify. 誤差対策TODO. -0.0が返りうる。
    assert(!equals(y, 0));
    if (x >= 0) return x - fabs(y)*fabs(per(x, y));
    return x - fabs(y)*floor(x, fabs(y));
}
int seisuu(ld x) { return (int)x; } // 整数部分. 誤差対策TODO
int modf(ld x) {
	if (x < 0) return ceill(x);
	else return floorl(x);
}
// 正なら+EPS, 負なら-EPSしてから、文字列に直して小数点以下を捨てる?
int seisuu(int x, int y) {
    assert(y != 0);
    return x / y;
}
int seisuu(ld x, ld y) { // 誤差対策TODO
    assert(!equals(y, 0));
    return (int)(x / y);
}

template <class T> pair<T, T> max(const pair<T, T> &a, const pair<T, T> &b) {
    if (a.first > b.first or a.first == b.first && a.second > b.second) return a;
    return b;
}
template <class T> pair<T, T> min(const pair<T, T> &a, const pair<T, T> &b) {
    if (a.first < b.first or a.first == b.first && a.second < b.second) return a;
    return b;
}

template <class T> bool chmax(T &a, const T& b) {
    if (a < b) { a = b; return true; } return false;
}
template <class T> bool chmin(T &a, const T& b) {
    if (a > b) { a = b; return true; } return false;
}
template <class T> T mid(T a, T b, T c) { // 誤差対策TODO
    return a + b + c - max({a, b, c}) - min({a, b, c});
}
template <class T> void Sort(T &a, T &b, bool rev = false) { 
    if (rev == false) {  // TODO テンプレート引数
        if (a > b) swap(a, b);
    } else {
        if (b > a) swap(b, a);
    }
}
template <class T> void sort(T &a, T &b, T &c, bool rev = false) {
    if (rev == false) { 
        if (a > b) swap(a, b); if (a > c) swap(a, c); if (b > c) swap(b, c);
    } else {
        if (c > b) swap(c, b); if (c > a) swap(c, a); if (b > a) swap(b, a);
    }
}
template <class T> void sort(T &a, T &b, T &c, T &d, bool rev = false) {
    if (rev == false) { 
        if (a > b) swap(a, b); if (a > c) swap(a, c);  if (a > d) swap(a, d);
        if (b > c) swap(b, c); if (b > d) swap(b, d); if (c > d) swap(c, d);
    } else {
        if (d > c) swap(d, c); if (d > b) swap(d, b); if (d > a) swap(d, a);
        if (c > b) swap(c, b); if (c > a) swap(c, a); if (b > a) swap(b, a);
    }
}

struct custom_hash {
    static uint64_t splitmix64(uint64_t x) {
        x += 0x9e3779b97f4a7c15;
        x = (x ^ (x >> 30)) * 0xbf58476d1ce4e5b9;
        x = (x ^ (x >> 27)) * 0x94d049bb133111eb;
        return x ^ (x >> 31);
    }

    size_t operator()(uint64_t x) const {
        static const uint64_t FIXED_RANDOM = chrono::steady_clock::now().time_since_epoch().count();
        return splitmix64(x + FIXED_RANDOM);
    }
};

class Compress {
public:
    int sz = 0;
    // gp_hash_table<int, int, custom_hash> Z, UZ;
    unordered_map<int, int> Z;    // 元の値 -> 圧縮した値
    unordered_map<int, int> UZ;   // 圧縮した値 -> 元の値

    Compress(const vector<int> &V, int base = 0) {
        this->sz = base;
        set<int> s(V.begin(), V.end());

        for (int x : s) {
            this->Z[x] = this->sz;
            this->UZ[this->sz] = x;
            this->sz++;
        }
    }
    
    Compress(const vector<int> &V1, const vector<int> &V2, int base = 0) {
        this->sz = base;
        vector<int> V3 = V2;
        V3.insert(V3.end(), V1.begin(), V1.end());
        set<int> s(V3.begin(), V3.end());

        for (int x : s) {
            this->Z[x] = this->sz;
            this->UZ[this->sz] = x;
            this->sz++;
        }
    }

    Compress(const vector<int> &V1, const vector<int> &V2, const vector<int> &V3, int base = 0) {
        this->sz = base;
        vector<int> V4 = V1;
        V4.insert(V4.end(), V2.begin(), V2.end());
        V4.insert(V4.end(), V3.begin(), V3.end());
        set<int> s(V4.begin(), V4.end());

        for (int x : s) {
            this->Z[x] = this->sz;
            this->UZ[this->sz] = x;
            this->sz++;
        }
    }

    Compress(const vector<int> &V1, const vector<int> &V2,
            const vector<int> &V3, const vector<int> &V4, int base = 0) {
        this->sz = base;
        vector<int> V5 = V1;
        V5.insert(V5.end(), V2.begin(), V2.end());
        V5.insert(V5.end(), V3.begin(), V3.end());
        V5.insert(V5.end(), V4.begin(), V4.end());
        set<int> s(V5.begin(), V5.end());

        for (int x : s) {
            this->Z[x] = this->sz;
            this->UZ[this->sz] = x;
            this->sz++;
        }
    }

    vector<int> zip(const vector<int> &V) {
        vector<int> ret = V;
        for (int i = 0; i < (int)V.size(); i++) {
            ret[i] = Z[ret[i]];
        }
        return ret;
    }

    vector<int> unzip(const vector<int> &V) {
        vector<int> ret = V;
        for (int i = 0; i < (int)V.size(); i++) {
            ret[i] = UZ[ret[i]];
        }
        return ret;
    }

    int size() { return sz; }

    int encode(int x) { return Z[x]; }
    int decode(int x) {
        if (UZ.find(x) == UZ.end()) return -1; // xが元の配列に存在しないとき
        return UZ[x];
    }
};

class UnionFind {
public:
	UnionFind() = default;
    UnionFind(int N) : par(N), sz(N, 1) {
        iota(par.begin(), par.end(), 0);
    }
	int root(int x) {
		if (par[x] == x) return x;
		return (par[x] = root(par[x]));
	}
	bool unite(int x, int y) {
		int rx = root(x);
		int ry = root(y);
        if (rx == ry) return false;
		if (sz[rx] < sz[ry]) swap(rx, ry);
		sz[rx] += sz[ry];
		par[ry] = rx;
        return true;
	}
	bool issame(int x, int y) { return (root(x) == root(y)); }
	int size(int x) { return sz[root(x)]; }
    vector<vector<int>> groups(int N) {
        vector<vector<int>> G(N);
        for (int x = 0; x < N; x++) {
            G[root(x)].push_back(x);
        }
		G.erase( remove_if(G.begin(), G.end(),
            [&](const vector<int>& V) { return V.empty(); }), G.end());
        return G;
    }
private:
	vector<int> par, sz;
};

template<typename T>
struct BIT {
    int N;             // 要素数
    vector<T> bit[2];  // データの格納先
    BIT(int N_, int x = 0) {
        N = N_ + 1;
        bit[0].assign(N, 0); bit[1].assign(N, 0);
        if (x != 0) {
            for (int i = 0; i < N; i++) add(i, x);
        }
    }
    BIT(const vector<int> &A) {
        N = A.size() + 1;
        bit[0].assign(N, 0); bit[1].assign(N, 0);
        for (int i = 0; i < (int)A.size(); i++) add(i, A[i]);
    }
    void add_sub(int p, int i, T x) {
        while (i < N) { bit[p][i] += x; i += (i & -i); }
    }
    void add(int l, int r, T x) {
        add_sub(0, l + 1, -x * l); add_sub(0, r + 1, x * r);
        add_sub(1, l + 1, x); add_sub(1, r + 1, -x);
    }
    void add(int i, T x) { add(i, i + 1, x); }
    T sum_sub(int p, int i) {
        T ret = 0;
        while (i > 0) { ret += bit[p][i]; i -= (i & -i); }
        return ret;
    }
    T sum(int i) { return sum_sub(0, i) + sum_sub(1, i) * i; }
    T sum(int l, int r) { return sum(r) - sum(l); }
    T get(int i) { return sum(i, i + 1); }
    void set(int i, T x) { T s = get(i); add(i, -s + x); }
};

template<int mod> class Modint {
public:
    int val = 0;
    Modint(int x = 0) { while (x < 0) x += mod; val = x % mod; }
    Modint(const Modint &r) { val = r.val; }

    Modint operator -() { return Modint(-val); } // 単項
    Modint operator +(const Modint &r) { return Modint(*this) += r; }
    Modint operator +(const int &q) { Modint r(q); return Modint(*this) += r; }
    Modint operator -(const Modint &r) { return Modint(*this) -= r; }
    Modint operator -(const int &q) { Modint r(q); return Modint(*this) -= r; }
    Modint operator *(const Modint &r) { return Modint(*this) *= r; }
    Modint operator *(const int &q) { Modint r(q); return Modint(*this) *= r; }
    Modint operator /(const Modint &r) { return Modint(*this) /= r; }
    Modint operator /(const int &q) { Modint r(q); return Modint(*this) /= r; }
    
    Modint& operator ++() { val++; if (val >= mod) val -= mod; return *this; } // 前置
    Modint operator ++(signed) { ++*this; return *this; } // 後置
    Modint& operator --() { val--; if (val < 0) val += mod; return *this; }
    Modint operator --(signed) { --*this; return *this; }
    Modint &operator +=(const Modint &r) { val += r.val; if (val >= mod) val -= mod; return *this; }
    Modint &operator +=(const int &q) { Modint r(q); val += r.val; if (val >= mod) val -= mod; return *this; }
    Modint &operator -=(const Modint &r) { if (val < r.val) val += mod; val -= r.val; return *this; }
    Modint &operator -=(const int &q) { Modint r(q);  if (val < r.val) val += mod; val -= r.val; return *this; }
    Modint &operator *=(const Modint &r) { val = val * r.val % mod; return *this; }
    Modint &operator *=(const int &q) { Modint r(q); val = val * r.val % mod; return *this; }
    Modint &operator /=(const Modint &r) {
        int a = r.val, b = mod, u = 1, v = 0;
        while (b) {int t = a / b; a -= t * b; swap(a, b); u -= t * v; swap(u, v);}
        val = val * u % mod; if (val < 0) val += mod;
        return *this;
    }
    Modint &operator /=(const int &q) {
        Modint r(q); int a = r.val, b = mod, u = 1, v = 0;
        while (b) {int t = a / b; a -= t * b; swap(a, b); u -= t * v; swap(u, v);}
        val = val * u % mod; if (val < 0) val += mod;
        return *this;
    }
    bool operator ==(const Modint& r) { return this -> val == r.val; }
    bool operator <(const Modint& r) { return this -> val < r.val; }
    bool operator >(const Modint& r) { return this -> val > r.val; }
    bool operator !=(const Modint& r) { return this -> val != r.val; }
};

using mint = Modint<MOD>;

istream &operator >>(istream &is, mint& x) {
    int t; is >> t; x = t; return (is);
}
ostream &operator <<(ostream &os, const mint& x) {
    return os << x.val;
}
mint modpow(const mint &x, int n) {
    if (n < 0) return (mint)1 / modpow(x, -n); // 未verify
    assert(n >= 0);
    if (n == 0) return 1;
    mint t = modpow(x, n / 2);
    t = t * t;
    if (n & 1) t = t * x;
    return t;
}

int modpow(__int128_t x, int n, int mod) {
    assert(n >= 0 && mod > 0); // TODO: n <= -1
    __int128_t ret = 1;
    while (n > 0) {
        if (n % 2 == 1) ret = ret * x % mod;
        x = x * x % mod;
        n /= 2;
    }
    return ret;
}
int modinv(__int128_t x, int mod) {
    assert(mod > 0);
    // assert(x > 0);
    if (x == 1 or x == 0) return 1;
    return mod - modinv(mod % x, mod) * (mod / x) % mod;
}

istream &operator >>(istream &is, __int128_t& x) {
    string S; is >> S;
    __int128_t ret = 0;
    int f = 1;
    if (S[0] == '-') f = -1; 
    for (int i = 0; i < S.length(); i++)
        if ('0' <= S[i] && S[i] <= '9')
            ret = ret * 10 + S[i] - '0';
    x = ret * f;
    return (is);
}
ostream &operator <<(ostream &os, __int128_t x) {
    ostream::sentry s(os);
    if (s) {
        __uint128_t tmp = x < 0 ? -x : x;
        char buffer[128]; char *d = end(buffer);
        do {
            --d; *d = "0123456789"[tmp % 10]; tmp /= 10;
        } while (tmp != 0);
        if (x < 0) { --d; *d = '-'; }
        int len = end(buffer) - d;
        if (os.rdbuf()->sputn(d, len) != len) os.setstate(ios_base::badbit);
    }
    return os;
}

__int128_t stoll(string &S) {
    __int128_t ret = 0; int f = 1;
    if (S[0] == '-') f = -1; 
    for (int i = 0; i < S.length(); i++)
        if ('0' <= S[i] && S[i] <= '9') ret = ret * 10 + S[i] - '0';
    return ret * f;
}
__int128_t gcd(__int128_t a, __int128_t b) { return b ? gcd(b, a % b) : a; }
__int128_t lcm(__int128_t a, __int128_t b) {
    return a / gcd(a, b) * b;
    // lcmが__int128_tに収まる必要あり
}

string to_string(ld x, int k) { // xの小数第k位までをstring化する
    assert(k >= 0);
    stringstream ss;
    ss << setprecision(k + 2) << x;
    string s = ss.str();
    if (s.find('.') == string::npos) s += '.';
    int pos = s.find('.');
    for (int i = 0; k >= (int)s.size() - 1 - pos; i++) s += '0';
    s.pop_back();
    if (s.back() == '.') s.pop_back();
    return s;

    // stringstream ss; // 第k+1位を四捨五入して第k位まで返す
    // ss << setprecision(k + 1) << x;
    // string s = ss.str();
    // if (s.find('.') == string::npos) s += '.';
    // int pos = s.find('.');
    // for (int i = 0; k > (int)s.size() - 1 - pos; i++) s += '0';
    // if (s.back() == '.') s.pop_back();
    // return s;
}
string to_string(__int128_t x) {
    string ret = "";
    if (x < 0) { ret += "-"; x *= -1; }
    while (x) { ret += (char)('0' + x % 10); x /= 10; }
    reverse(ret.begin(), ret.end());
    return ret;
}
string to_string(char c) { string s = ""; s += c; return s; }

template<class T> size_t HashCombine(const size_t seed,const T &v) {
    return seed^(hash<T>()(v)+0x9e3779b9+(seed<<6)+(seed>>2));
}
template<class T,class S> struct hash<pair<T,S>>{
    size_t operator()(const pair<T,S> &keyval) const noexcept {
        return HashCombine(hash<T>()(keyval.first), keyval.second);
    }
};
template<class T> struct hash<vector<T>>{
    size_t operator()(const vector<T> &keyval) const noexcept {
        size_t s=0;
        for (auto&& v: keyval) s=HashCombine(s,v);
        return s;
    }
};
template<int N> struct HashTupleCore{
    template<class Tuple> size_t operator()(const Tuple &keyval) const noexcept{
        size_t s=HashTupleCore<N-1>()(keyval);
        return HashCombine(s,get<N-1>(keyval));
    }
};
template <> struct HashTupleCore<0>{
    template<class Tuple> size_t operator()(const Tuple &keyval) const noexcept{ return 0; }
};
template<class... Args> struct hash<tuple<Args...>>{
    size_t operator()(const tuple<Args...> &keyval) const noexcept {
        return HashTupleCore<tuple_size<tuple<Args...>>::value>()(keyval);
    }
};

vector<mint> _fac, _finv, _inv;
void COMinit(int N) {
    _fac.resize(N + 1); _finv.resize(N + 1);  _inv.resize(N + 1);
    _fac[0] = _fac[1] = 1; _finv[0] = _finv[1] = 1; _inv[1] = 1;
    for (int i = 2; i <= N; i++) {
        _fac[i] = _fac[i-1] * mint(i);
        _inv[i] = -_inv[MOD % i] * mint(MOD / i);
        _finv[i] = _finv[i - 1] * _inv[i];
    }
}

mint FAC(int N) {
    if (N < 0) return 0; return _fac[N];
}
mint COM(int N, int K) {
    if (N < K) return 0; if (N < 0 or K < 0) return 0;
    return _fac[N] * _finv[K] * _finv[N - K];
}
mint PERM(int N, int K) {
    if (N < K) return 0; if (N < 0 or K < 0) return 0;
    return _fac[N] *  _finv[N - K];
}
mint NHK(int N, int K) { // initのサイズに注意
    if (N == 0 && K == 0)  return 1;
    return COM(N + K - 1, K);
}

#pragma endregion

vector<string> split_str(string S, char c) {
    vector<string> ret;
    stringstream ss;
    for (int i = 0; i < S.size(); i++) {
        if (S[i] == c) {
            ret.pb(ss.str());
            ss.str("");
            ss.clear();
        } else {
            ss << S[i];
        }
    }
    ret.pb(ss.str());
    return ret;
}

signed main() {
    int N;
    while (cin >> N, N) {
        vector<int> A(N);
        for (int i = 0; i < N; i++) cin >> A[i];

        int ans = 0;
        while (true) {
            bool fin = true;
            for (int i = 0; i < (int)A.size(); i++) {
                if (A[i] != i + 1) {
                    fin = false;
                    break;
                }
            }
            if (fin) break;
            
            int cnt = 0;
            for (int i = 0; i < (int)A.size(); i++) {
                A[i]--;
                cnt++;
            }
            A.pb(cnt);
            vector<int> B;
            for (int i = 0; i < (int)A.size(); i++) {
                if (A[i]) B.pb(A[i]);
            }
            A = B;
            ans++;
            if (ans == 10001) break;
        }
        if (ans == 10001) cout << -1 << endl;
        else cout << ans << endl;
    }
}
accuracy: 1
time_ms: 180
memory_kb: 3516
final_rank: 16

code_snippet: #include <iostream>
#include <vector>
using namespace std;

bool is_tri(vector<int> b) {
    int i = 1;
    for (int bi : b) {
        if (bi != i++) return false;
    }
    return true;
}

int main() {
    const int MAX_CNT = 10000;

    while (true) {
        int N;
        cin >> N;
        if (N == 0) break;
        vector<int> b(N);
        for (int &bi : b) cin >> bi;
        
        int cnt = 0;
        while (!is_tri(b)) {
            if (cnt++ == MAX_CNT) {
                cnt = -1; break;
            }
            vector<int> tmp;
            for (int bi : b) {
                if (--bi > 0) tmp.push_back(bi);
            }
            tmp.push_back(b.size());
            b = tmp;
        };
        cout << cnt << endl;
    }

    return 0;
}
accuracy: 1
time_ms: 80
memory_kb: 3472
final_rank: 6

code_snippet: #include <iostream>
using namespace std;

bool is_tri(int b[], int N) {
    for (int i = 1; i <= N; ++i) {
        if (b[i] != i) return false;
    }
    return true;
}

int main() {
    const int MAX_CNT = 10000;

    while (true) {
        int N, b[2000000] = {};
        cin >> N; if (N == 0) break;
        for (int i = 1; i <= N; ++i) {
            cin >> b[i];
        }
        
        int cnt = 0;
        while (!is_tri(b, N)) {
            if (cnt++ == MAX_CNT) {
                cnt = -1; break;
            }

            int j = 1;
            for (int i = 1; i <= N; ++i) {
                if (--b[i] > 0) {
                    if (j != i) {
                        b[j] = b[i]; b[i] = 0;
                    }
                    ++j;
                }
            }
            b[j] = N; N = j;
        };
        cout << cnt << endl;
    }

    return 0;
}
accuracy: 1
time_ms: 40
memory_kb: 11252
final_rank: 19

code_snippet: #pragma GCC optimize("Ofast")
#include <bits/stdc++.h>
using namespace std;
typedef long long int ll;
typedef unsigned long long int ull;

mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
ll myRand(ll B) {
    return (ull)rng() % B;
}
inline double time() {
    return static_cast<long double>(chrono::duration_cast<chrono::nanoseconds>(chrono::steady_clock::now().time_since_epoch()).count()) * 1e-9;
}

int main(){
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    int n;
    while (cin >> n, n) {
        vector<int> b(n);
        for (int i = 0; i < n; ++i) {
            cin >> b[i];
        }
        int cnt = 0;
        while (1) {
            bool ok = true;
            for (int i = 0; i < b.size(); ++i) {
                if (b[i] != i+1) {
                    ok = false; break;
                }
            }
            if (ok) {
                cout << cnt << "\n";
                break;
            }
            cnt++;
            if (cnt > 10000) {
                cout << -1 << "\n";
                break;
            }
            vector<int> nb;
            for (int i = 0; i < b.size(); ++i) {
                if (b[i] > 1) {
                    nb.push_back(b[i]-1);
                }
            }
            nb.push_back(b.size());
            swap(b,nb);
        }
    }
}
accuracy: 1
time_ms: 90
memory_kb: 3456
final_rank: 8

code_snippet: #include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  while (cin >> n, n) {
    vector<int> v;
    v.clear();
    for (int i = 0; i < n; ++i) {
      int x;
      cin >> x;
      v.push_back(x);
    }
    int ans = 0, cnt = 0;
    int t = 1;
    for (int i = 0; i < v.size(); ++i) {
      if (v[i]) {
        if (v[i] == t)
          ++t;
        else
          break;
      }
    }
    if (t - 1 == v.size()) {
      cout << 0 << endl;
      continue;
    }
    int flag = 1;
    while (flag) {
      cnt = 0;
      ans++;
      if (ans > 10000) {
        ans = -1;
        break;
      }
      for (int i = 0; i < v.size(); ++i) {
        if (v[i]) {
          v[i]--;
          cnt++;
        }
      }
      v.push_back(cnt);
      int a = 1, b = 0;
      for (int j = 0; j < v.size(); ++j) {
        if (v[j]) {
          if (v[j] == a)
            ++a;
          else {
            break;
          }
        }
        b = j + 1;
      }
      if (b == v.size())
        break;
    }
    if (flag)
      cout << ans << endl;
  }
  return 0;
}
accuracy: 1
time_ms: 470
memory_kb: 3264
final_rank: 20

code_snippet: #include <bits/stdc++.h>
using namespace std;
vector<int> f(vector<int> v) {
  vector<int> res;
  for (int i = 0; i < v.size(); i++)
    if (v[i] > 0)
      res.push_back(v[i]);
  return res;
}
bool check(vector<int> v) {
  for (int i = 0; i < v.size(); i++)
    if (v[i] != i + 1)
      return false;
  return true;
}
int main() {
  int n;
  while (cin >> n, n) {
    vector<int> v;
    v.clear();
    for (int i = 0; i < n; ++i) {
      int x;
      cin >> x;
      v.push_back(x);
    }
    int ans = 0, cnt = 0;
    while (!check(v)) {
      ans++;
      if (ans > 10000) {
        ans = -1;
        break;
      }
      int size = v.size();
      for (int i = 0; i < size; ++i) {
        v[i]--;
      }
      v.push_back(size);
      v = f(v);
    }
    cout << ans << endl;
  }
  return 0;
}
accuracy: 1
time_ms: 210
memory_kb: 3120
final_rank: 17

code_snippet: #include <algorithm>
#include <cstdio>
#include <deque>
#include <iostream>
#define F first
#define S second
using namespace std;
bool check(deque<int> &deq, int counter) {
  for (int i = deq.size() - 1; i >= 0; i--) {
    if (deq[i] != counter)
      return false;
    else
      counter--;
  }
  return counter == 0;
}
int main() {
  int N;
  while (true) {
    cin >> N;
    if (!N)
      break;
    deque<int> deq;
    for (int i = 0; i < N; i++) {
      int input;
      cin >> input;
      deq.push_back(input);
    }
    if (check(deq, N)) {
      cout << 0 << endl;
      continue;
    }
    bool fin = true;
    for (int m = 1; m <= 10000; m++) {
      fin = true;
      int counter = 0;
      deque<int> n_deq;
      for (int i = 0; i < deq.size(); i++) {
        if (deq[i] >= 1) {
          counter++;
          deq[i]--;
        }
        if (deq[i] >= 1) {
          n_deq.push_back(deq[i]);
        }
      }
      deq = n_deq;
      deq.push_back(counter);
      if (check(deq, counter)) {
        cout << m << endl;
        fin = false;
        break;
      }
    }
    if (fin)
      cout << -1 << endl;
  }
  return 0;
}
accuracy: 1
time_ms: 350
memory_kb: 3172
final_rank: 18

code_snippet: #include <algorithm>
#include <deque>
#include <iostream>
using namespace std;
bool Check(deque<int> &deq) {
  int cnt = deq.size();
  for (int i = deq.size() - 1; i >= 0; i--) {
    if (deq[i] != cnt)
      return false;
    cnt--;
  }
  return true;
}
bool Do(deque<int> &deq) {
  for (int i = 1; i <= 10000; i++) {
    for (int iu = 0; iu < deq.size(); iu++)
      deq[iu]--;
    int next = deq.size();
    deq.erase(remove(deq.begin(), deq.end(), 0), deq.end());
    deq.push_back(next);
    if (Check(deq)) {
      cout << i << endl;
      return true;
    }
  }
  return false;
}
int main() {
  int N;
  while (cin >> N, N) {
    deque<int> deq;
    for (int i = 0; i < N; i++) {
      int in;
      cin >> in;
      deq.push_back(in);
    }
    if (Check(deq)) {
      cout << 0 << endl;
      continue;
    }
    if (!Do(deq))
      cout << -1 << endl;
  }
  return 0;
}
accuracy: 1
time_ms: 90
memory_kb: 3100
final_rank: 4

code_snippet: #include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  while (cin >> n, n) {
    int num[2000] = {}, co = n, sum = 0;
    for (int i = 0; i < n; i++)
      cin >> num[i];
    for (int i = 0;; i++) {
      bool kawa = 1;
      if (i == 10000) {
        cout << -1 << endl;
        break;
      }
      for (int j = 0; j < co && kawa; j++)
        if (num[j] != j + 1)
          kawa = 0;
      if (kawa) {
        cout << i << endl;
        break;
      }
      for (int j = 0; j < co; j++)
        num[j] -= 1;
      num[co] = co;
      for (int j = 0; j <= co; j++) {
        if (num[j] == 0) {
          for (int k = j + 1; k <= co; k++) {
            if (num[k] != 0) {
              swap(num[j], num[k]);
              break;
            }
          }
        }
      }
      for (int j = 0; j <= co + 1; j++) {
        if (num[j] == 0 || j == co + 1) {
          co = j;
          break;
        }
      }
    }
  }
}
accuracy: 1
time_ms: 140
memory_kb: 3108
final_rank: 14

code_snippet: #include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  while (cin >> n, n) {
    int num[2000] = {}, co = n;
    for (int i = 0; i < n; i++)
      cin >> num[i];
    for (int i = 0;; i++) {
      bool kawa = 1;
      if (i == 10000) {
        cout << -1 << endl;
        break;
      }
      for (int j = 0; j < co && kawa; j++)
        if (num[j] != j + 1)
          kawa = 0;
      if (kawa) {
        cout << i << endl;
        break;
      }
      for (int j = 0; j < co; j++)
        num[j] -= 1;
      num[co] = co;
      for (int j = 0; j <= co; j++) {
        if (num[j] == 0) {
          for (int k = j + 1; k <= co; k++) {
            if (num[k] != 0) {
              swap(num[j], num[k]);
              break;
            }
          }
        }
      }
      for (int j = co + 1; j >= 0; j--) {
        if (num[j] != 0) {
          co = j + 1;
          break;
        }
      }
    }
  }
}
accuracy: 1
time_ms: 90
memory_kb: 3100
final_rank: 4

code_snippet: #include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  while (cin >> n, n) {
    int num[2000] = {}, co = n;
    for (int i = 0; i < n; i++)
      cin >> num[i];
    bool NA = 0;
    for (int i = 0; !NA && i < 10001; i++) {
      bool kawa = 1;
      for (int j = 0; j < co && kawa; j++)
        if (num[j] != j + 1)
          kawa = 0;
      if (kawa) {
        NA = 1;
        cout << i << endl;
      }
      num[co] = co + 1;
      for (int j = 0; j <= co; j++) {
        if (num[j] == 1)
          for (int k = j + 1; k <= co && num[j] == 1; k++)
            if (num[k] != 1)
              swap(num[j], num[k]);
        num[j]--;
        if (num[j] == 0)
          co = j - 1;
      }
      co++;
    }
    if (!NA)
      cout << -1 << endl;
  }
}
accuracy: 1
time_ms: 120
memory_kb: 3100
final_rank: 12

code_snippet: #include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  while (cin >> n, n) {
    int num[2000] = {}, co = n;
    for (int i = 0; i < n; i++)
      cin >> num[i];
    bool NA = 0;
    for (int i = 0; !NA && i < 10000; i++) {
      bool kawa = 1;
      for (int j = 0; j < co && kawa; j++)
        if (num[j] != j + 1)
          kawa = 0;
      if (kawa) {
        NA = 1;
        cout << i << endl;
      }
      num[co] = co + 1;
      for (int j = 0; j <= co; j++) {
        if (num[j] == 1)
          for (int k = j + 1; k <= co && num[j] == 1; k++)
            if (num[k] != 1)
              swap(num[j], num[k]);
        num[j]--;
      }
      for (int j = co + 1; j >= 0; j--) {
        if (num[j] != 0) {
          co = j + 1;
          break;
        }
      }
    }
    if (!NA)
      cout << -1 << endl;
  }
}
accuracy: 1
time_ms: 110
memory_kb: 3096
final_rank: 9

code_snippet: #include <algorithm>
#include <cstdio>
#include <vector>
#define LIMIT 10000
using namespace std;
bool ck(vector<int> &v) {
  for (int i = 0; i < v.size(); i++)
    if (v[i] != i + 1)
      return false;
  return true;
}
main() {
  int n, i, j, s, x, l;
  vector<int> tri;
  for (i = 1; i < 1999; i++)
    tri.push_back(i * (i + 1) / 2);
  for (; scanf("%d", &n), n;) {
    vector<int> v;
    for (s = i = 0; i < n; i++) {
      scanf("%d", &x);
      s += x;
      v.push_back(x);
    }
    vector<int>::iterator idx = find(tri.begin(), tri.end(), s);
    i = LIMIT + 1;
    if (idx != tri.end()) {
      for (i = 0; i <= LIMIT && !ck(v); i++) {
        l = v.size();
        for (j = 0; j < l; j++)
          v[j]--;
        v.erase(remove(v.begin(), v.end(), 0), v.end());
        v.push_back(l);
      }
    }
    printf("%d\n", i > LIMIT ? -1 : i);
  }
}
accuracy: 1
time_ms: 40
memory_kb: 2684
final_rank: 2

code_snippet: #include <algorithm>
#include <cstdio>
#include <vector>
#define LIMIT 10000
using namespace std;
bool ck(vector<int> &v) {
  for (int i = 0; i < v.size(); i++)
    if (v[i] != i + 1)
      return false;
  return true;
}
main() {
  int n, i, j, s, x, l;
  vector<int> tri;
  for (i = 1; i < 1199; i++)
    tri.push_back(i * (i + 1) / 2);
  for (; scanf("%d", &n), n;) {
    vector<int> v;
    for (s = i = 0; i < n; i++) {
      scanf("%d", &x);
      s += x;
      v.push_back(x);
    }
    vector<int>::iterator idx = find(tri.begin(), tri.end(), s);
    i = LIMIT + 1;
    if (idx != tri.end()) {
      for (i = 0; i <= LIMIT && !ck(v); i++) {
        l = v.size();
        for (j = 0; j < l; j++)
          v[j]--;
        v.erase(remove(v.begin(), v.end(), 0), v.end());
        v.push_back(l);
      }
    }
    printf("%d\n", i > LIMIT ? -1 : i);
  }
}
accuracy: 1
time_ms: 10
memory_kb: 2808
final_rank: 1

code_snippet: #include <bits/stdc++.h>
using namespace std;
using ll = long long;

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    int n;
    auto f = [&](vector<int> a){
        for(int i = 0; i < a.size(); i++){
            if(i + 1 != a[i])return false;
        }
        return true;
    };
    auto update = [&](vector<int> a){
        vector<int> res;
        for(int i = 0; i < a.size(); i++){
            if(a[i] >= 2)res.push_back(a[i] - 1);
        }
        res.push_back(a.size());
        return res;
    };
    while(cin >> n, n){
        vector<int> b(n);
        for(auto &&v:b)cin >> v;
        int ans = 0;
        while(!f(b)){
            ans++;
            if(ans > 10000){
                ans = -1;
                break;
            }
            b = update(b);
        }
        cout << ans << '\n';
    }
}
accuracy: 1
time_ms: 120
memory_kb: 3456
final_rank: 13

code_snippet: #include <iostream>
using namespace std;
int main(void) {
	int a[1000],n,b[1000],k,t,flag,i,j;
	for (;;)
	{
		cin >> n;
		if (n == 0) {
			break;
		}
		for (i = 0; i < 1000; i++) {
			a[i] = 0;
			b[i] = 0;
		}
		flag = 1;
		for (i = 0; i < n; i++)
			cin >> a[i];
		for (j = 0; j < n; j++) {
			if (a[j] != j + 1)
			{
				flag = 0;
				break;
			}
		}
		if (flag) {
			cout << 0 << endl;
			continue;
		}
		k = n;
		for (i = 0; ; i++)
		{
			t = 0;
			for (j = 0; j < k; j++)
			{
				a[j]--;
				if (a[j] > 0)
					b[t++] = a[j];
			}
			b[t++] = k;
			if (t >= 1000) {
				cout << (-1) << endl;
				break;
			}
			flag = 1;
			for (j = 0; j < t; j++) {
				if (b[j] != j + 1)
				{
					flag = 0;
					break;
				}
			}
			if (flag) {
				cout << i+1 << endl;
				break;
			}
			for (j = 0; j < t;j++)
			{
				a[j] = b[j];
			}
			k = t;
			if (i > 10000) {
				cout << ( -1) << endl;
				break;
			}
		}
	}
	//system("pause");
}
accuracy: 1
time_ms: 20
memory_kb: 3428
final_rank: 3

code_snippet: #include <bits/stdc++.h>
using namespace std;
int main(){
  while (true){
    int N;
    cin >> N;
    if (N == 0){
      break;
    }
    vector<int> b(N);
    for (int i = 0; i < N; i++){
      cin >> b[i];
    }
    int ans = 0;
    while (true){
      bool ok = true;
      for (int i = 0; i < N; i++){
        if (b[i] != i + 1){
          ok = false;
        }
      }
      if (ok){
        cout << ans << endl;
        break;
      }
      ans++;
      if (ans > 10000){
        cout << -1 << endl;
        break;
      }
      vector<int> b2;
      for (int i = 0; i < N; i++){
        if (b[i] > 1){
          b2.push_back(b[i] - 1);
        }
      }
      b2.push_back(N);
      N = b2.size();
      swap(b, b2);
    }
  }
}
accuracy: 1
time_ms: 80
memory_kb: 3488
final_rank: 7

code_snippet: #include <bits/stdc++.h>
using namespace std;
#define ll long long

signed main() {
    while(true) {
        int n; cin >> n;
        if(n == 0) break;
        vector<int> b(n);
        for(int i=0; i<n; i++) cin >> b[i];
        int i = 0;
        bool flg = true;
        for(int j=0; j<b.size(); j++) {
            if(j+1 != b[j]) {
                flg = false;
                break;
            }
        }
        if(flg) {
            cout << 0 << endl;
            continue;
        }
        for(; i<10000; i++) {
            vector<int> next;
            for(int j=0; j<b.size(); j++) {
                if(b[j] > 1) next.push_back(b[j] - 1);
            }
            next.push_back(b.size());
            b = next;
            bool flg = true;
            for(int j=0; j<b.size(); j++) {
                if(j+1 != b[j]) {
                    flg = false;
                    break;
                }
            }
            if(flg) {
                break;
            }
        }
        if(i == 10000) {
            cout << -1 << endl;
        } else {
            cout << i+1 << endl;
        }
    }
}
accuracy: 1
time_ms: 110
memory_kb: 3160
final_rank: 10