#include<bits/stdc++.h>
#define endl '\n'
#define int long long
#define pii pair<int, int>
using namespace std;
const int N = 2e5 + 100 , MXN = 1e6 + 100 , INF = 0x3f3f3f3f3f3f3f3f;
int arr[N];
void solve(){
    int n;cin >> n;
    int a_one = 1, a_zero = 1, cnt0 = 0;
    for(int i = 2;i <= n;i++){
        cin >> arr[i];
        if(arr[i] == 0)a_one = 0;
        if(arr[i] == 1)a_zero = 0;
        if(a_zero) cnt0++;
    }
    if(a_one){
        cout << 1 << endl;
        return;
    }
    if(a_zero){
        cout << n - 1 << endl;
        return;
    }
    for(int i = n;i >= 2;i--){
        if(arr[i] == 1){
            if(i == n)cout << 2 << endl;
            else if(cnt0) cout << n - i + 2 << endl;
            else cout << n - i + 1 << endl;
            break;
        }
    }
}
signed main(){
    ios_base::sync_with_stdio(0),cin.tie(0),cout.tie(0);
    // freopen("C:\\Users\\charl\\Desktop\\C++\\_in.txt", "r", stdin);
    // freopen("C:\\Users\\charl\\Desktop\\C++\\_out.txt", "w", stdout);

    int T = 1;
    //cin >> T;
    for(int i = 1;i <= T;i++){
        // cout << "Case #" << i << ": ";
        solve();
    }

}