#include <bits/stdc++.h>
using namespace std;
const int N = 100005;
int arr[N];
int main() {
    int n;
    cin >> n;

    bool zero = false, one = false;
    for(int i = 0; i < n - 1; i++) {
        cin >> arr[i];
        if(arr[i] == 0) zero = true;
        if(arr[i] == 1) one = true;
    }

    int pt = n - 1;
    while(pt >= 1 && arr[pt - 1] == 0) {
        pt--;
    }

    if(!zero) cout << "1\n";
    else if(!one) cout << n - 1 << "\n";
    else if(pt == n - 1) cout << "2\n";
    else cout << (n - pt) << "\n";
}