#include "bits/stdc++.h"
using namespace std;

#define rep(i, a, b) for(int i = a; i < (b); ++i)
#define all(x) begin(x), end(x)
#define sz(x) (int)(x).size()
typedef long long ll;
typedef pair<int, int> pii;
typedef vector<int> vi;

int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  
  const int N = 1e6+7;
  int n, k;
  cin >> n >> k;
  k--;
  vector<vi> indices(N);
  vi a(n);
  vi value_idx(n);
  for (int i = 0; i < n; i++) {
    cin >> a[i];
    value_idx[i] = indices[a[i]].size();
    indices[a[i]].push_back(i);
  }

  int64_t ans = 0;
  multiset<int> bad_idxs;
  for (int i =0; i < n; i++) {
    int j = value_idx[i];
    int before = j - k - 1;
    if (before >= 0) {
      int val = indices[a[i]][before];
      bad_idxs.erase(bad_idxs.find(val));
    }
    int after = j - k;
    if (after >= 0) {
      int val = indices[a[i]][after];
      bad_idxs.insert(val);
    }
    int lim = -1;
    if (bad_idxs.size()) {
      lim = *bad_idxs.rbegin();
    }
    ans += i - lim;
  }
  cout << ans << '\n';
}