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

const int MAXN = 101010;

int n; bool a[MAXN];
int main() {
    cin.tie(0); ios_base::sync_with_stdio(0);
    cin >> n;
    for (int i = 2; i <= n; i++)
        cin >> a[i];
    
    a[2] = 1;
    bool x = 1;
    for (int i = 3; i <= n; i++) {
        x &= a[i];
    }
    if (x) return !(cout << 1);
    if (a[n]) return !(cout << 2);
    int p = -1;
    for (int i = n; i >= 2; i--) {
        if (a[i]) {
            p = i; break;
        }
    }
    return !(cout << n + 1 - p);
}