#include <bits/stdc++.h>
using namespace std;
const int MAXN = 8;
const int MAXR = 1;
const int MAXC = 1;
const int MAXBITS = 64;
const int INF = (int)1e9;
int dx[] = {-1, 0, 1, 0};
int dy[] = {0, 1, 0, -1};
int dx8[] = {-1, -1, -1, 0, 0, 1, 1, 1};
int dy8[] = {-1, 0, 1, -1, 1, -1, 0, 1};
priority_queue<int, vector<int>, greater<int>> q1;
priority_queue<int, vector<int>, less<int>> q2;
void l() { ; }
int arr[MAXN];
int main(void) {
  ios::sync_with_stdio(false);
  cin.tie(NULL);
  int n, k;
  cin >> n >> k;
  vector<int> v(n);
  for (int i = 0; i < n; ++i) cin >> v[i];
  ;
  ;
  int st = 0;
  int en = 0;
  map<int, int> m;
  long long int ans = 0;
  while (en < n) {
    l();
    ++m[v[en]];
    while (st <= en && m[v[en]] >= k) {
      ;
      ;
      ans += n - en;
      --m[v[st]];
      ++st;
    }
    ++en;
  }
  cout << ans;
  return 0;
}
