#include <iostream>
using namespace std;
const int N = 1e6 + 10;
typedef long long LL;
LL a[N];
LL q[N], tt, hh;
int vis[N];
LL ans;

void solve() {
    LL n, k;
    scanf("%lld%lld", &n, &k);
    for (int i = 1; i <= n; i++) {
        scanf("%lld", &a[i]);
    }
    LL last = 0;
    for (int i = 1; i <= n; i++) {
        if (++vis[a[i]] == k) {
            LL tmp = tt - last;
            LL tmp1 = tmp * (tmp + 1) / 2;
            ans += tmp1 + tmp * (last - hh);
        }
        while (hh <= tt && vis[a[i]] == k) {
            hh++;
            vis[a[q[hh]]]--;
            
            last = tt;
        }
        q[++tt] = i;
    }
    if (hh <= tt) {
        LL tmp = tt - last;
        LL tmp1 = tmp * (tmp + 1) / 2;
        ans += tmp1 + tmp * (last - hh);
    }
    printf("%lld\n", ans);
}

int main() {
    solve();
    return 0;
}