#include<bits/stdc++.h>
using namespace std;
#define INF 0x3f3f3f3f
#define PI acos(-1)
#define io ios::sync_with_stdio(false); cin.tie(0); cout.tie(0)
#define mem(a,b) memset((a),(b),sizeof(a))
typedef long long ll;
typedef unsigned long long ull;
#define int long long

const int maxn = 1e5 + 10;

int n, a[maxn];

void solve() {
    cin >> n;
    int cnt0 = 0;
    int cnt1 = 0;
    for(int i = 1; i < n; i++) {
        cin >> a[i];
        if(a[i] == 0) cnt0++;
        else cnt1++;
    }
    if(cnt1 == 0) {
        cout << cnt0 << '\n';
    } else if(cnt0 == 0) {
        cout << "1\n";
    } else if(cnt0 == 1) {
        if(a[1] == 0) cout << "1\n";
        else cout << "2\n";
    } else {
        int cnt = 0;
        for(int i = n - 1; i >= 1; i--) {
            if(a[i] == 1) break;
            else cnt++; 
        }
        cout << max(2 * 1ll, cnt + 1) << '\n';
    }
}

signed main(){
    io;
    int T = 1;
    //cin >> T;
    while(T--) {
        solve();
    }
    return 0;
}