#include<bits/stdc++.h>
#define int long long
#define fi first
#define se second
#define MULT_TEST 0
using namespace std;
typedef long double ldb;
typedef unsigned long long ull;
const int INF = 0x3f3f3f3f;
const int MOD = 998244353;
const int N = 1000006;
int col[N], from[N];
vector<int> E[N];
inline int read() {
    int w = 0, f = 1;
    char ch = getchar();
    while (ch < '0' || ch > '9') {
        if (ch == '-') f = -1;
        ch = getchar();
    }
    while (ch >= '0' && ch <= '9') {
        w = (w << 1) + (w << 3) + ch - 48;
        ch = getchar();
    }
    return w * f;
}
inline void Solve() {
    int n, k;
    n = read(), k = read();
    vector<int> T;
    for (int i = 1; i <= n; i++) {
        col[i] = read();
        T.push_back(col[i]);
        E[col[i]].push_back(i);
    }
    sort(T.begin(), T.end());
    T.erase(unique(T.begin(), T.end()), T.end());
    for (auto c : T) {
        int sz = E[c].size();
        for (int i = k - 1; i < sz; i++) from[E[c][i]] = E[c][i - k + 1];
    }
    int ans = 0, mx = 0;
    for (int i = 1; i <= n; i++) {
        mx = max(mx, from[i]);
        ans += i - mx;
    }
    printf("%lld\n", ans);
}
signed main() {
    int _ = 1;
#if MULT_TEST
    _ = read();
#endif 
    while (_--) Solve();
    return 0;
}