#include <bits/stdc++.h>
#define BIT(n) (1LL << (n))
#define BITF(n, i) (((n) >> i) & 1)
#define REP(i, n) for (int i = 0; i < n; i++)
#define REPB(i, n) for (int i = 0; i < BIT(n); i++)
#define REPS(i, x) for (int i = 1; i <= x; i++)
#define REPR(i, n) for (int i = n; i >= 0; i--)
#define REPZ(i, x) for (int i = 0; i <= x; i++)
#define FOR(i, m, n) for (int i = m; i < n; i++)
#define FORA(i, n) for (auto &&i : n)
#define FORS(i, m, n) for (int i = m; i <= n; i++)
using namespace std;
#define PRINTARR(x, y)                                                         \
  cerr << #x << "=\n";                                                         \
  for (auto itr = x; itr != y; itr++)                                          \
    cerr << *itr << " ";                                                       \
  cerr << endl;
#define PRINTARR2(x, i0, i1)                                                   \
  cerr << #x << "=\n";                                                         \
  for (int ii0 = 0; ii0 < i0; ii0++) {                                         \
    for (int ii1 = 0; ii1 < i1; ii1++)                                         \
      cerr << x[ii0][ii1] << " ";                                              \
    cerr << endl;                                                              \
  }
#define DUMPOUT cerr
// vector
template < typename T > istream &operator>>(istream &is, vector< T > &vec) {
  for (T &x : vec)
    is >> x;
  return is;
}
// pair
template < typename T, typename U >
ostream &operator<<(ostream &os, pair< T, U > &pair_var) {
  os << "(" << pair_var.first << ", " << pair_var.second << ")";
  return os;
}
// vector
template < typename T >
ostream &operator<<(ostream &os, const vector< T > &vec) {
  os << "{";
  REP(i, (int)vec.size())
  os << vec[i] << (i + 1 == (int)vec.size() ? "" : ", ");
  os << "}";
  return os;
}
// map
template < typename T, typename U >
ostream &operator<<(ostream &os, map< T, U > &map_var) {
  os << "{";
  FORA(itr, map_var) {
    os << *itr;
    itr++;
    if (itr != map_var.end())
      os << ", ";
    itr--;
  }
  os << "}";
  return os;
}
// set
template < typename T > ostream &operator<<(ostream &os, set< T > &set_var) {
  os << "{";
  FORA(itr, set_var) {
    os << *itr;
    itr++;
    if (itr != set_var.end())
      os << ", ";
    itr--;
  }
  os << "}";
  return os;
}
void dump_func() { DUMPOUT << endl; }
template < class Head, class... Tail >
void dump_func(Head &&head, Tail &&... tail) {
  DUMPOUT << head;
  if (sizeof...(Tail) > 0)
    DUMPOUT << ", ";
  dump_func(std::move(tail)...);
}
#ifdef DEBUG_
#define DEB
#define DUMP(...)                                                              \
  DUMPOUT << "  " << string(#__VA_ARGS__) << ": "                              \
          << "[" << to_string(__LINE__) << ":" << __FUNCTION__ << "]" << endl  \
          << "    ",                                                           \
      dump_func(__VA_ARGS__)
#else
#define DEB if (false)
#define DUMP(...)
#endif

#define ALL(v) v.begin(), v.end()
#define fst first
#define snd second
#define mp make_pair
#define pb push_back
#define epb emplace_back
#define int long long
#define pint pair< int, int >
#define ld long double
using namespace std;
template < class T > bool chmax(T &a, const T &b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template < class T > bool chmin(T &a, const T &b) {
  if (a > b) {
    a = b;
    return 1;
  }
  return 0;
}
template < class T > using vec = std::vector< T >;
template < class T > void print(const T &x) { cout << x << "\n"; }
const int MOD = 1000000007, INF0 = 1061109567, INF = INF0 * INF0;
const double EPS = 1e-10, PI = acos(-1.0);
const int dx[4] = {1, 0, -1, 0}, dy[4] = {0, 1, 0, -1};
#define MAXN 200200
//----//
int a[MAXN];
int sum[MAXN];

signed main() {
  cin.tie(0), ios::sync_with_stdio(false);
  cout << fixed << setprecision(10);
  int N, K;
  cin >> N >> K;
  REP(i, N) cin >> a[i];
  REP(i, N) { sum[i + 1] = (sum[i] + a[i]); }
  REP(i, N) {
    sum[i + 1] += K;
    sum[i + 1] -= i + 1;
    sum[i + 1] %= K;
  }
  vec< pint > x(N + 1);

  REP(i, N + 1) { x[i] = mp(sum[i], i); }
  sort(ALL(x));
  // FORA(e, x) DUMP(e.fst, e.snd);
  int ans = 0;
  int prev = 0;
  int now = 0;
  while (prev < N + 1) {
    vec< int > l;
    int p = x[prev].fst;
    now = prev;
    while (p == x[now].fst && now < N + 1) {
      l.pb(x[now].snd);
      now++;
    }
    // FORA(e, l) cerr << e << " ";
    // cerr << "\n";
    REP(i, (int)l.size()) {
      int val = l[i] - K;
      int x = distance(l.begin(), upper_bound(ALL(l), val));
     // DUMP(i, x);
      x = i - x + 1;
      x--;
      //      int x = distance(lower_bound(ALL(l), val), l.begin() ); - 1;
   //   DUMP(x);
     // DUMP(ans);
      if (x > 0) {
        ans += x;
      }
    }
    // DUMP(l.size());
    //    REP(i, prev, now) {}

    if (now == N + 1)
      break;
    prev = now;
  }
  print(ans);

  /*  int cnt = 0;
    REP(i, 1) {
      // i+1<=j<=N
      FORS(j, i + 1, N) {
        int val = sum[j] - sum[i];
        if (val % K == (j - i))
          cnt++;
      }
    }
    print(cnt);*/
}

Measured memory_bytes: 8692