#include <bits/stdc++.h>
using namespace std;
int n, k, a[400010];
map<int, int> m;
set<pair<int, int> > s;
long long ans = 0;
int main() {
  cin >> n >> k;
  for (int i = 1; i <= n; ++i) cin >> a[i];
  a[0] = 0;
  for (int l = 1, r = 0; l <= n; ++l) {
    s.erase(make_pair(-m[a[l - 1]], a[l - 1]));
    m[a[l - 1]]--;
    s.insert(make_pair(-m[a[l - 1]], a[l - 1]));
    while (-s.begin()->first < k) {
      ++r;
      if (r >= n + 1) break;
      s.erase(make_pair(-m[a[r]], a[r]));
      m[a[r]]++;
      s.insert(make_pair(-m[a[r]], a[r]));
    }
    ans += max(n + 1 - r, 0);
  }
  cout << ans << endl;
  return 0;
}
