#include <bits/stdc++.h>

using namespace std;
long long n, a[500005], d = 0, s = 1;
map < long long, long long > b;
int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    cin >> n;
    for (long long i = 1; i <= n; i++) {
        cin >> a[i];
        b[a[i]]++;
    }
    for (long long i = 1; i <= n; i++) {
        if (b[a[i]] >= 2) {
            d = d + (b[a[i]] * (b[a[i]] - 1) / 2);
            b[a[i]] = 0;
        }
    }
    cout << d;
    return 0;
}

# $\color{black}{\text{le}}$$\color{gray}{\text{duc}}$$\color{darkgray}{\text{trung}}$$\color{white}{\text{anh}}$