#include <bits/stdc++.h>
using namespace std;
int n, a[100005];
 
bool f[100005] = {0};
 
int main () {
    freopen ("count1s.in", "r", stdin);
    freopen ("count1s.out", "w", stdout);
    scanf ("%d", &n);
    int cnt = 0;
    for (int q = 1; q <= n; ++q) {
        scanf ("%d", &a[q]);
        if (a[q] == 1) cnt ++;
    }
    f[cnt] = true;
    int x0, x1;
    for (int q = 1; q <= n; ++q) {
        x0 = 0; x1 = 0;
        for (int w = q;w <= n; ++w) {
            if (a[w] == 0) x0 ++;
            else x1 ++;
            f[cnt - x1 + x0] = true;
        }
    }
    int ans = 0;
    for (int q = 0; q <= n; ++q) {
        if (f[q]) ans ++;
    }
    printf ("%d\n", ans);
    return 0;
}