#include <bits/stdc++.h>

using namespace std;

const int N = 1000005;

vector <int> where[N];
array <int, 2> t[N << 2];
int n, k, a[N], lazy[N << 2];

inline array <int, 2> operator + (const array <int, 2> &A, const array <int, 2> &B) {
  return A[0] == B[0] ? array <int, 2> ({A[0], A[1] + B[1]}) : min(A, B); 
}

void init (int u = 1, int b = 1, int e = n) {
  if (b == e) return void(t[u] = {0, 1});
  int mid = b + e >> 1;
  init(u << 1, b, mid), init(u << 1 | 1, mid + 1, e);
  t[u] = t[u << 1] + t[u << 1 | 1];
}

inline void push (int u, int b, int e) {
  t[u][0] += lazy[u];
  if (b ^ e) lazy[u << 1] += lazy[u], lazy[u << 1 | 1] += lazy[u];
  lazy[u] = 0;
}

void update (int l, int r, int v, int u = 1, int b = 1, int e = n) {
  if (lazy[u]) push(u, b, e);
  if (b > r or e < l) return;
  if (b >= l and e <= r) {
    lazy[u] += v;
    return push(u, b, e);
  }
  int mid = b + e >> 1;
  update(l, r, v, u << 1, b, mid), update(l, r, v, u << 1 | 1, mid + 1, e);
  t[u] = t[u << 1] + t[u << 1 | 1];
}

array <int, 2> query (int l, int r, int u = 1, int b = 1, int e = n) {
  if (b > r or e < l) return {N, 1};
  if (lazy[u]) push(u, b, e);
  if (b >= l and e <= r) return t[u];
  int mid = b + e >> 1;
  return query(l, r, u << 1, b, mid) + query(l, r, u << 1 | 1, mid + 1, e);
}

int main() {
  cin >> n >> k;
  for (int i = 1; i <= n; ++i) {
    scanf("%d", a + i);
    if (where[a[i]].empty()) where[a[i]].emplace_back(0);
    where[a[i]].emplace_back(i);
  }
  init();
  long long ans = 0;
  for (int i = 1; i <= n; ++i) {
    int x = a[i];
    auto &vec = where[x];
    int pos = lower_bound(vec.begin(), vec.end(), i) - vec.begin();
    if (pos >= k) update(vec[pos - k] + 1, vec[pos - k + 1], 1);
    if (pos > k) update(vec[pos - 1 - k] + 1, vec[pos - k], -1);
    auto here = query(1, i);
    if (!here[0]) ans += here[1];
  }
  cout << ans << '\n';
  return 0;
}