Problem p02585 (C++) — buggy submission, verdict: Runtime Error

/*
#include <boost/multiprecision/cpp_dec_float.hpp>
#include <boost/multiprecision/cpp_int.hpp>

#include <boost/rational.hpp>
*/
#include <bits/stdc++.h>
using namespace std;
#define _GLIBCXX_DEBUG
#define rep(i, t) for (ll i = (ll)(0); i < (ll)(t); i++)
#define rep2(i, s, t) for (ll i = (ll)(s); i < (ll)(t); i++)
#define rep3(i, t) for (ll i = (ll)(1); i <= (ll)(t); i++)
#define rep4(i, s, t) for (ll i = (ll)(s); i <= (ll)(t); i++)
#define repr(i, t) for (ll i = (t - 1); i >= (0); i--)
#define repr2(i, s, t) for (ll i = (t - 1); i >= (s); i--)
#define repr3(i, t) for (ll i = (t); i >= (1); i--)
#define repr4(i, s, t) for (ll i = (t); i >= (s); i--)
using ll = long long;
using ld = long double;
using ull = unsigned long long;
using uint = unsigned;
using pcc = pair<char, char>;
using pll = pair<ll, ll>;
using pii = pair<int, int>;
using pdd = pair<double, double>;
using tuplis = array<ll, 3>;
template <class T> using pq = priority_queue<T, vector<T>, greater<T>>;
inline const ll LINF = 0x1fffffffffffffff;
inline const ll MINF = 0x7fffffffffff;
inline const int INF = 0x3fffffff;
inline const int mod = 1000000007;
// inline const int mod=998244353;

inline const ld DINF = numeric_limits<ld>::infinity();
inline const ld EPS = 1e-9;
inline const ld PI = acos(-1);
// const ll dx[] ={0,1,0,-1,1,-1,1,-1};
// const ll dy[] ={1,0,-1,0,1,1,-1,-1};
inline const bool grindin(const int i, const int j, const int H, const int W) {
  return i >= 0 && i < H && j >= 0 && j < W;
}
inline const ll dx[] = {0, 1, 0, -1};
inline const ll dy[] = {1, 0, -1, 0};
#define is_low(c) ('a' <= c) && (c <= 'z')
#define is_upp(c) ('A' <= c) && (c <= 'Z')
#define each1(i, a) for (auto &&i : a)
#define each2(x, y, a) for (auto &&[x, y] : a)
#define each3(x, y, z, a) for (auto &&[x, y, z] : a)
#define rrep(n) for (ll i = (n); i--;)
#define stlen(s) ll s.size() - 1
#define all(v) begin(v), end(v)
#define range(v, a) begin(v), begin(v) + a
#define range2(v, a, b) begin(v) + a, begin(v) + b
#define range3(v, a) begin(v) + 1, begin(v) + a + 1
#define range4(v, a, b) begin(v) + a + 1, begin(v) + b + 1
#define allr(v) rbegin(v), v.rend(v)
#define ranger(v, a) rbegin(v), rbegin(v) + a
#define ranger2(v, a, b) rbegin(v) + a, rbegin(v) + b
#define ranger3(v, a) rbegin(v) + 1, rbegin(v) + a + 1
#define ranger4(v, a, b) rbegin(v) + a + 1, rbegin(v) + b + 1
#define cout(n) cout << std::fixed << std::setprecision(n)
// #define sum(...) accumulate(all(__VA_ARGS__),0LL)
#define dsum(...) accumulate(all(__VA_ARGS__), 0.0L)
#define elif else if
#define unless(a) if (!(a))
#define mp make_pair
#define mt make_tuple
#define INT(...)                                                               \\
  int __VA_ARGS__;                                                             \\
  in(__VA_ARGS__)
#define LL(...)                                                                \\
  ll __VA_ARGS__;                                                              \\
  in(__VA_ARGS__)
#define ULL(...)                                                               \\
  ull __VA_ARGS__;                                                             \\
  in(__VA_ARGS__)
#define STR(...)                                                               \\
  string __VA_ARGS__;                                                          \\
  in(__VA_ARGS__)
#define CHR(...)                                                               \\
  char __VA_ARGS__;                                                            \\
  in(__VA_ARGS__)
#define DBL(...)                                                               \\
  double __VA_ARGS__;                                                          \\
  in(__VA_ARGS__)
#define LD(...)                                                                \\
  ld __VA_ARGS__;                                                              \\
  in(__VA_ARGS__)
#define Sort(a) sort(all(a))
#define Rev(a) reverse(all(a))
#define Uniq(a)                                                                \\
  sort(all(a)); a.erase(unique(all(a))),end(a))
#define vec(type, name, ...) vector<type> name(__VA_ARGS__)
#define VEC(type, name, size)                                                  \\
  vector<type> name(size);                                                     \\
  in(name)
#define vv(type, name, h, ...)                                                 \\
  vector<vector<type>> name(h, vector<type>(__VA_ARGS__))
#define VV(type, name, h, w)                                                   \\
  vector<vector<type>> name(h, vector<type>(w));                               \\
  in(name)
template <class T> inline const auto min(const T &a) {
  return *min_element(all(a));
}
template <class T> inline const auto max(const T &a) {
  return *max_element(all(a));
}
inline const ll popcnt(const ull a) { return __builtin_popcountll(a); }
inline const ll gcd(ll a, ll b) {
  while (b) {
    ll c = b;
    b = a % b;
    a = c;
  }
  return a;
}
inline const ll lcm(ll a, ll b) {
  unless(a && b) return 0;
  return a * b / gcd(a, b);
}
inline const ll intpow(ll a, ll b) {
  ll ans = 1;
  while (b) {
    if (b & 1)
      ans *= a;
    a *= a;
    b /= 2;
  }
  return ans;
}
inline const ll modpow(ll a, ll b, ll p = mod) {
  ll ans = 1;
  while (b) {
    if (b & 1)
      (ans *= a) %= p;
    (a *= a) %= p;
    b /= 2;
  }
  return ans;
}
template <class T, class U> inline const bool chmin(T &a, const U &b) {
  if (a > b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T, class U> inline const bool chmax(T &a, const U &b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
inline const vector<ll> iota(const ll n) {
  vector<ll> a(n);
  iota(all(a), 0);
  return a;
}
inline const vector<pll> factor(ull x) {
  vector<pll> ans;
  for (ull i = 2; i * i <= x; i++)
    if (x % i == 0) {
      ans.push_back({i, 1});
      while ((x /= i) % i == 0)
        ans.back().second++;
    }
  if (x != 1)
    ans.push_back({x, 1});
  return ans;
}
inline const map<ll, ll> factor_map(ull x) {
  map<ll, ll> ans;
  for (ull i = 2; i * i <= x; i++)
    if (x % i == 0) {
      ans[i] = 1;
      while ((x /= i) % i == 0)
        ans[i]++;
    }
  if (x != 1)
    ans[x] = 1;
  return ans;
}
inline const vector<ll> divisor(ull x) {
  vector<ll> ans;
  for (ull i = 2; i * i <= x; i++)
    if (x % i == 0)
      ans.push_back(i);
  rrep(ans.size() - (ans.back() * ans.back() == x)) ans.push_back(x / ans[i]);
  return ans;
}
inline const int scan() { return getchar(); }
inline const void scan(int &a) { scanf("%d", &a); }
inline const void scan(unsigned &a) { scanf("%u", &a); }
inline const void scan(long &a) { scanf("%ld", &a); }
inline const void scan(long long &a) { scanf("%lld", &a); }
inline const void scan(char &a) {
  do {
    a = getchar();
  } while (a == ' ' || a == '\\n');
}
inline const void scan(float &a) { scanf("%f", &a); }
inline const void scan(double &a) { scanf("%lf", &a); }
inline const void scan(long double &a) { scanf("%Lf", &a); }
inline const void scan(string &a) { cin >> a; }
template <class T> inline const void scan(vector<T> &a) {
  for (auto &&i : a)
    scan(i);
}
template <class T, size_t size> inline const void scan(array<T, size> &a) {
  for (auto &&i : a)
    scan(i);
}
template <class T, class L> inline const void scan(pair<T, L> &p) {
  scan(p.first);
  scan(p.second);
}
template <class T, size_t size> inline const void scan(T (&a)[size]) {
  for (auto &&i : a)
    scan(i);
}
inline const void in() {}
template <class Head, class... Tail>
inline const void in(Head &head, Tail &...tail) {
  scan(head);
  in(tail...);
}
inline const int ctoi(const char c) {
  if (c >= 'a' && c <= 'z') {
    return c - 'a';
  }
  if (c >= 'A' && c <= 'Z') {
    return c - 'A';
  }
  return -1;
}
inline const void print() { putchar(' '); }
inline const void print(const bool a) { printf("%d", a); }
inline const void print(const int a) { printf("%d", a); }
inline const void print(const unsigned a) { printf("%u", a); }
inline const void print(const long a) { printf("%ld", a); }
inline const void print(const unsigned long long a) { printf("%llu", a); }
inline const void print(const char a) { printf("%c", a); }
inline const void print(const double a) { printf("%.15f", a); }
inline const void print(const long double a) { printf("%.15Lf", a); }
inline const void print(const string &a) {
  for (auto &&i : a)
    print(i);
}
template <class T> inline const void print(const vector<T> &a) {
  if (a.empty())
    return;
  print(a[0]);
  for (auto i = a.begin(); ++i != a.end();) {
    putchar(' ');
    print(*i);
  }
}
template <class T> inline const void print(const deque<T> &a) {
  if (a.empty())
    return;
  print(a[0]);
  for (auto i = a.begin(); ++i != a.end();) {
    putchar(' ');
    print(*i);
  }
}
template <class T, size_t size> inline const void print(const T (&a)[size]) {
  print(a[0]);
  for (auto i = a; ++i != end(a);) {
    putchar(' ');
    print(*i);
  }
}
template <class T> inline const void print(const T &a) { cout << a; }
inline const int out() {
  putchar('\\n');
  return 0;
}
template <class T> inline const int out(const T &t) {
  print(t);
  putchar('\\n');
  return 0;
}
template <class Head, class... Tail>
inline const int out(const Head &head, const Tail &...tail) {
  print(head);
  putchar(' ');
  out(tail...);
  return 0;
}
inline const int first(const bool i) { return out(i ? "first" : "second"); }
inline const int yes(const bool i) { return out(i ? "yes" : "no"); }
inline const int Yes(const bool i) { return out(i ? "Yes" : "No"); }
inline const int YES(const bool i) { return out(i ? "YES" : "NO"); }
inline const int possible(const bool i) {
  return out(i ? "possible" : "impossible");
}
inline const int Possible(const bool i) {
  return out(i ? "Possible" : "Impossible");
}
inline const int POSSIBLE(const bool i) {
  return out(i ? "POSSIBLE" : "IMPOSSIBLE");
}

using Graph = vector<vector<int>>;
using Graphw = vector<vector<pair<ll, ll>>>;
using mat = vector<vector<ll>>;
using vec = vector<ll>;

/*
namespace mp = boost::multiprecision;
// 任意長整数型
using Bint = mp::cpp_int;
// 仮数部長が32の浮動小数点数型
using Real32 = mp::number<mp::cpp_dec_float<32>>;
// 仮数部長が1024の浮動小数点数型
using Real1024 = mp::number<mp::cpp_dec_float<1024>>;
// 有理数型
using Rat = boost::rational<Bint>;
*/

template <typename T> struct SparseTable {
  vector<vector<T>> st;
  vector<int> lookup;

  SparseTable(const vector<T> &v) {
    int b = 0;
    while ((1 << b) <= v.size())
      ++b;
    st.assign(b, vector<T>(1 << b));
    for (int i = 0; i < v.size(); i++) {
      st[0][i] = v[i];
    }
    for (int i = 1; i < b; i++) {
      for (int j = 0; j + (1 << i) <= (1 << b); j++) {
        st[i][j] = max(st[i - 1][j], st[i - 1][j + (1 << (i - 1))]);
      }
    }
    lookup.resize(v.size() + 1);
    for (int i = 2; i < lookup.size(); i++) {
      lookup[i] = lookup[i >> 1] + 1;
    }
  }

  inline T rmq(int l, int r) {
    int b = lookup[r - l];
    return max(st[b][l], st[b][r - (1 << b)]);
  }
};

signed main() {

  INT(N, K);
  int P[N];
  rep(i, N) {
    cin >> P[i];
    P[i]--;
  }
  ll C[N];
  rep(i, N) { cin >> C[i]; }
  bool seen[N];
  ll ans = -intpow(10, 18);
  rep(i, N) seen[i] = false;
  rep(i, N) {
    if (seen[i])
      continue;
    vector<int> cycle;
    int now = i;
    seen[now] = true;
    cycle.push_back(now);

    while (true) {
      int next = P[now];
      if (seen[next])
        break;
      seen[next] = true;
      cycle.push_back(next);
      now = next;
    }
    int roopsize = cycle.size();

    vector<int> cycle2;
    rep(j, 2) rep(i, roopsize) cycle2.push_back(cycle[i]);
    vector<ll> sum(2 * roopsize);
    rep(i, 2 * roopsize) {
      if (i == 0)
        sum[i] = C[cycle2[i]];
      else
        sum[i] = sum[i - 1] + C[cycle2[i]];
    }
    SparseTable<ll> ST(sum);
    if (K <= roopsize) {
      rep(i, roopsize) {
        rep(j, K) {
          if (i == 0)
            chmax(ans, sum[i + j]);
          else
            chmax(ans, sum[i + j] - sum[i - 1]);
        }
      }
    } else {
      if (sum[roopsize - 1] <= 0) {
        rep(i, roopsize) {
          rep(j, roopsize) {
            if (i == 0)
              chmax(ans, sum[i + j]);
            else
              chmax(ans, sum[i + j] - sum[i - 1]);
          }
        }
      } else {
        rep(i, roopsize) {
          rep(j, roopsize) {
            if (i == 0)
              chmax(ans, sum[roopsize - 1] * (K / roopsize - 1) + sum[i + j]);
            else
              chmax(ans, sum[roopsize - 1] * (K / roopsize - 1) + sum[i + j] -
                             sum[i - 1]);
          }
        }
        rep(i, roopsize) {
          rep(j, K % roopsize) {
            if (i == 0)
              chmax(ans, sum[roopsize - 1] * (K / roopsize) + sum[i + j]);
            else
              chmax(ans, sum[roopsize - 1] * (K / roopsize) + sum[i + j] -
                             sum[i - 1]);
          }
        }
      }
    }
  }
  out(ans);
}

Error: 0

Fixed submission:

/*
#include <boost/multiprecision/cpp_dec_float.hpp>
#include <boost/multiprecision/cpp_int.hpp>

#include <boost/rational.hpp>
*/
#include <bits/stdc++.h>
using namespace std;
#define _GLIBCXX_DEBUG
#define rep(i, t) for (ll i = (ll)(0); i < (ll)(t); i++)
#define rep2(i, s, t) for (ll i = (ll)(s); i < (ll)(t); i++)
#define rep3(i, t) for (ll i = (ll)(1); i <= (ll)(t); i++)
#define rep4(i, s, t) for (ll i = (ll)(s); i <= (ll)(t); i++)
#define repr(i, t) for (ll i = (t - 1); i >= (0); i--)
#define repr2(i, s, t) for (ll i = (t - 1); i >= (s); i--)
#define repr3(i, t) for (ll i = (t); i >= (1); i--)
#define repr4(i, s, t) for (ll i = (t); i >= (s); i--)
using ll = long long;
using ld = long double;
using ull = unsigned long long;
using uint = unsigned;
using pcc = pair<char, char>;
using pll = pair<ll, ll>;
using pii = pair<int, int>;
using pdd = pair<double, double>;
using tuplis = array<ll, 3>;
template <class T> using pq = priority_queue<T, vector<T>, greater<T>>;
inline const ll LINF = 0x1fffffffffffffff;
inline const ll MINF = 0x7fffffffffff;
inline const int INF = 0x3fffffff;
inline const int mod = 1000000007;
// inline const int mod=998244353;

inline const ld DINF = numeric_limits<ld>::infinity();
inline const ld EPS = 1e-9;
inline const ld PI = acos(-1);
// const ll dx[] ={0,1,0,-1,1,-1,1,-1};
// const ll dy[] ={1,0,-1,0,1,1,-1,-1};
inline const bool grindin(const int i, const int j, const int H, const int W) {
  return i >= 0 && i < H && j >= 0 && j < W;
}
inline const ll dx[] = {0, 1, 0, -1};
inline const ll dy[] = {1, 0, -1, 0};
#define is_low(c) ('a' <= c) && (c <= 'z')
#define is_upp(c) ('A' <= c) && (c <= 'Z')
#define each1(i, a) for (auto &&i : a)
#define each2(x, y, a) for (auto &&[x, y] : a)
#define each3(x, y, z, a) for (auto &&[x, y, z] : a)
#define rrep(n) for (ll i = (n); i--;)
#define stlen(s) ll s.size() - 1
#define all(v) begin(v), end(v)
#define range(v, a) begin(v), begin(v) + a
#define range2(v, a, b) begin(v) + a, begin(v) + b
#define range3(v, a) begin(v) + 1, begin(v) + a + 1
#define range4(v, a, b) begin(v) + a + 1, begin(v) + b + 1
#define allr(v) rbegin(v), v.rend(v)
#define ranger(v, a) rbegin(v), rbegin(v) + a
#define ranger2(v, a, b) rbegin(v) + a, rbegin(v) + b
#define ranger3(v, a) rbegin(v) + 1, rbegin(v) + a + 1
#define ranger4(v, a, b) rbegin(v) + a + 1, rbegin(v) + b + 1
#define cout(n) cout << std::fixed << std::setprecision(n)
// #define sum(...) accumulate(all(__VA_ARGS__),0LL)
#define dsum(...) accumulate(all(__VA_ARGS__), 0.0L)
#define elif else if
#define unless(a) if (!(a))
#define mp make_pair
#define mt make_tuple
#define INT(...)                                                               \\
  int __VA_ARGS__;                                                             \\
  in(__VA_ARGS__)
#define LL(...)                                                                \\
  ll __VA_ARGS__;                                                              \\
  in(__VA_ARGS__)
#define ULL(...)                                                               \\
  ull __VA_ARGS__;                                                             \\
  in(__VA_ARGS__)
#define STR(...)                                                               \\
  string __VA_ARGS__;                                                          \\
  in(__VA_ARGS__)
#define CHR(...)                                                               \\
  char __VA_ARGS__;                                                            \\
  in(__VA_ARGS__)
#define DBL(...)                                                               \\
  double __VA_ARGS__;                                                          \\
  in(__VA_ARGS__)
#define LD(...)                                                                \\
  ld __VA_ARGS__;                                                              \\
  in(__VA_ARGS__)
#define Sort(a) sort(all(a))
#define Rev(a) reverse(all(a))
#define Uniq(a)                                                                \\
  sort(all(a)); a.erase(unique(all(a))),end(a))
#define vec(type, name, ...) vector<type> name(__VA_ARGS__)
#define VEC(type, name, size)                                                  \\
  vector<type> name(size);                                                     \\
  in(name)
#define vv(type, name, h, ...)                                                 \\
  vector<vector<type>> name(h, vector<type>(__VA_ARGS__))
#define VV(type, name, h, w)                                                   \\
  vector<vector<type>> name(h, vector<type>(w));                               \\
  in(name)
template <class T> inline const auto min(const T &a) {
  return *min_element(all(a));
}
template <class T> inline const auto max(const T &a) {
  return *max_element(all(a));
}
inline const ll popcnt(const ull a) { return __builtin_popcountll(a); }
inline const ll gcd(ll a, ll b) {
  while (b) {
    ll c = b;
    b = a % b;
    a = c;
  }
  return a;
}
inline const ll lcm(ll a, ll b) {
  unless(a && b) return 0;
  return a * b / gcd(a, b);
}
inline const ll intpow(ll a, ll b) {
  ll ans = 1;
  while (b) {
    if (b & 1)
      ans *= a;
    a *= a;
    b /= 2;
  }
  return ans;
}
inline const ll modpow(ll a, ll b, ll p = mod) {
  ll ans = 1;
  while (b) {
    if (b & 1)
      (ans *= a) %= p;
    (a *= a) %= p;
    b /= 2;
  }
  return ans;
}
template <class T, class U> inline const bool chmin(T &a, const U &b) {
  if (a > b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T, class U> inline const bool chmax(T &a, const U &b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
inline const vector<ll> iota(const ll n) {
  vector<ll> a(n);
  iota(all(a), 0);
  return a;
}
inline const vector<pll> factor(ull x) {
  vector<pll> ans;
  for (ull i = 2; i * i <= x; i++)
    if (x % i == 0) {
      ans.push_back({i, 1});
      while ((x /= i) % i == 0)
        ans.back().second++;
    }
  if (x != 1)
    ans.push_back({x, 1});
  return ans;
}
inline const map<ll, ll> factor_map(ull x) {
  map<ll, ll> ans;
  for (ull i = 2; i * i <= x; i++)
    if (x % i == 0) {
      ans[i] = 1;
      while ((x /= i) % i == 0)
        ans[i]++;
    }
  if (x != 1)
    ans[x] = 1;
  return ans;
}
inline const vector<ll> divisor(ull x) {
  vector<ll> ans;
  for (ull i = 2; i * i <= x; i++)
    if (x % i == 0)
      ans.push_back(i);
  rrep(ans.size() - (ans.back() * ans.back() == x)) ans.push_back(x / ans[i]);
  return ans;
}
inline const int scan() { return getchar(); }
inline const void scan(int &a) { scanf("%d", &a); }
inline const void scan(unsigned &a) { scanf("%u", &a); }
inline const void scan(long &a) { scanf("%ld", &a); }
inline const void scan(long long &a) { scanf("%lld", &a); }
inline const void scan(char &a) {
  do {
    a = getchar();
  } while (a == ' ' || a == '\\n');
}
inline const void scan(float &a) { scanf("%f", &a); }
inline const void scan(double &a) { scanf("%lf", &a); }
inline const void scan(long double &a) { scanf("%Lf", &a); }
inline const void scan(string &a) { cin >> a; }
template <class T> inline const void scan(vector<T> &a) {
  for (auto &&i : a)
    scan(i);
}
template <class T, size_t size> inline const void scan(array<T, size> &a) {
  for (auto &&i : a)
    scan(i);
}
template <class T, class L> inline const void scan(pair<T, L> &p) {
  scan(p.first);
  scan(p.second);
}
template <class T, size_t size> inline const void scan(T (&a)[size]) {
  for (auto &&i : a)
    scan(i);
}
inline const void in() {}
template <class Head, class... Tail>
inline const void in(Head &head, Tail &...tail) {
  scan(head);
  in(tail...);
}
inline const int ctoi(const char c) {
  if (c >= 'a' && c <= 'z') {
    return c - 'a';
  }
  if (c >= 'A' && c <= 'Z') {
    return c - 'A';
  }
  return -1;
}
inline const void print() { putchar(' '); }
inline const void print(const bool a) { printf("%d", a); }
inline const void print(const int a) { printf("%d", a); }
inline const void print(const unsigned a) { printf("%u", a); }
inline const void print(const long a) { printf("%ld", a); }
inline const void print(const unsigned long long a) { printf("%llu", a); }
inline const void print(const char a) { printf("%c", a); }
inline const void print(const double a) { printf("%.15f", a); }
inline const void print(const long double a) { printf("%.15Lf", a); }
inline const void print(const string &a) {
  for (auto &&i : a)
    print(i);
}
template <class T> inline const void print(const vector<T> &a) {
  if (a.empty())
    return;
  print(a[0]);
  for (auto i = a.begin(); ++i != a.end();) {
    putchar(' ');
    print(*i);
  }
}
template <class T> inline const void print(const deque<T> &a) {
  if (a.empty())
    return;
  print(a[0]);
  for (auto i = a.begin(); ++i != a.end();) {
    putchar(' ');
    print(*i);
  }
}
template <class T, size_t size> inline const void print(const T (&a)[size]) {
  print(a[0]);
  for (auto i = a; ++i != end(a);) {
    putchar(' ');
    print(*i);
  }
}
template <class T> inline const void print(const T &a) { cout << a; }
inline const int out() {
  putchar('\\n');
  return 0;
}
template <class T> inline const int out(const T &t) {
  print(t);
  putchar('\\n');
  return 0;
}
template <class Head, class... Tail>
inline const int out(const Head &head, const Tail &...tail) {
  print(head);
  putchar(' ');
  out(tail...);
  return 0;
}
inline const int first(const bool i) { return out(i ? "first" : "second"); }
inline const int yes(const bool i) { return out(i ? "yes" : "no"); }
inline const int Yes(const bool i) { return out(i ? "Yes" : "No"); }
inline const int YES(const bool i) { return out(i ? "YES" : "NO"); }
inline const int possible(const bool i) {
  return out(i ? "possible" : "impossible");
}
inline const int Possible(const bool i) {
  return out(i ? "Possible" : "Impossible");
}
inline const int POSSIBLE(const bool i) {
  return out(i ? "POSSIBLE" : "IMPOSSIBLE");
}

using Graph = vector<vector<int>>;
using Graphw = vector<vector<pair<ll, ll>>>;
using mat = vector<vector<ll>>;
using vec = vector<ll>;

/*
namespace mp = boost::multiprecision;
// 任意長整数型
using Bint = mp::cpp_int;
// 仮数部長が32の浮動小数点数型
using Real32 = mp::number<mp::cpp_dec_float<32>>;
// 仮数部長が1024の浮動小数点数型
using Real1024 = mp::number<mp::cpp_dec_float<1024>>;
// 有理数型
using Rat = boost::rational<Bint>;
*/

template <typename T> class SparseTable {
  T **table;
  int *logtable;

public:
  SparseTable(vector<T> vec) {
    int maxlength = 0;
    while ((1 << (maxlength + 1)) <= vec.size())
      maxlength++;
    table = new T *[maxlength + 1];
    logtable = new int[vec.size() + 1];
    rep(i, maxlength + 1) {
      table[i] = new T[vec.size()];
      rep(j, vec.size() - (1 << i) + 1) {
        if (i)
          table[i][j] = max(table[i - 1][j], table[i - 1][j + (1 << (i - 1))]);
        else
          table[i][j] = vec[j];
      }
    }
    for (int i = 2; i <= vec.size(); i++) {
      logtable[i] = logtable[i >> 1] + 1;
    }
  }
  T query(int l, int r) {
    assert(l < r);
    int length = r - l;
    return max(table[logtable[length]][l],
               table[logtable[length]][r - (1 << logtable[length])]);
  }
};

signed main() {

  INT(N, K);
  int P[N];
  rep(i, N) {
    cin >> P[i];
    P[i]--;
  }
  ll C[N];
  rep(i, N) { cin >> C[i]; }
  bool seen[N];
  ll ans = -intpow(10, 15);
  rep(i, N) seen[i] = false;
  rep(i, N) {
    if (seen[i])
      continue;
    vector<int> cycle;
    int now = i;
    seen[now] = true;
    cycle.push_back(now);

    while (true) {
      int next = P[now];
      if (seen[next])
        break;
      seen[next] = true;
      cycle.push_back(next);
      now = next;
    }
    int roopsize = cycle.size();

    vector<int> cycle2;
    rep(j, 2) rep(i, roopsize) cycle2.push_back(cycle[i]);
    vector<ll> sum(2 * roopsize);
    rep(i, 2 * roopsize) {
      if (i == 0)
        sum[i] = C[cycle2[i]];
      else
        sum[i] = sum[i - 1] + C[cycle2[i]];
    }
    SparseTable<ll> ST(sum);
    if (K <= roopsize) {
      rep(i, roopsize) {

        if (i == 0)
          chmax(ans, ST.query(0, K));
        else
          chmax(ans, ST.query(i, i + K) - sum[i - 1]);
      }
    } else {
      if (sum[roopsize - 1] <= 0) {
        rep(i, roopsize) {
          if (i == 0)
            chmax(ans, ST.query(0, roopsize));
          else
            chmax(ans, ST.query(i, i + roopsize) - sum[i - 1]);
        }
      } else {
        rep(i, roopsize) {
          if (i == 0)
            chmax(ans, sum[roopsize - 1] * (K / roopsize - 1) +
                           ST.query(0, roopsize));
          else
            chmax(ans, sum[roopsize - 1] * (K / roopsize - 1) +
                           ST.query(i, i + roopsize) - sum[i - 1]);
        }
        rep(i, roopsize) {
          if (i == 0)
            chmax(ans, sum[roopsize - 1] * (K / roopsize) +
                           ST.query(0, K % roopsize));
          else
            chmax(ans, sum[roopsize - 1] * (K / roopsize) +
                           ST.query(i, i + K % roopsize) - sum[i - 1]);
        }
      }
    }
  }
  out(ans);
}