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

int main() {
    int n;
    cin >> n;
    vector<int>ans(n),a(n);
    for(int i = 0; i < n; i++) {
        cin >> a[i];
    }
    long long sum = 0;
    for(int i = n-2; i >= 0; i--) {
        if(a[i]) {
            if(a[i+1] != a[i]) {
                ans[i] = ans[i+1]+1;
            }
            else {
                ans[i] = 1;
            }
        }
        sum += ans[i];
        if(!a[i]) {
            if(a[i+1] != a[i]) {
                ans[i] = ans[i+1]+1;
            }
            else {
                ans[i] = 1;
            }
        }
    }
    cout << sum << endl;
}