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

int main() {
    int N;
    cin >> N;
    vector<int>A(N);
    for(int i = 0; i < N; i++) {
        cin >> A[i];
    }
    int l = 0,r = -1,cnt = 0;
    long long ans = 0;
    while (r < N) {
        while (cnt == 0) {
            r++;
            if(r == N) {
                break;
            }
            cnt += A[r]^1;
        }
        ans += N-r;
        cnt -= A[l]^1;
        l++;
    }
    cout << ans << endl;
}