#include <bits/stdc++.h>

#define el '\n'
#define Beevo ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);

typedef long long ll;
typedef long double ld;

using namespace std;

mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());

void testCase() {
    int n;
    cin >> n;

    int e[n - 1];
    for (int i = 0; i < n - 1; i++)
        cin >> e[i];

    if (count(e, e + n - 1, 1) == n - 1)
        return cout << 1, void();

    if (count(e, e + n - 1, 0) == n - 1)
        return cout << n - 1, void();

    if (n == 3)
        return cout << (e[1] ? 1 : 2), void();

    int cnt = 0;
    for (int i = n - 2; i >= 0; i--) {
        cnt++;

        if (e[i])
            break;
    }

    cout << max(cnt, 2);
}

signed main() {
    Beevo

    int t = 1;
//    cin >> t;

    while (t--)
        testCase();
}