#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define rep(i, s, e) for (int i = (int)(s); i < (int)(e); ++i)
#define all(a) (a).begin(),(a).end()

int main() {
    cin.tie(nullptr);
    ios_base::sync_with_stdio(false);
    
    int N;
    cin >> N;
    bool all0 = true;
    rep(i, 0, N) {
        int A;
        cin >> A;
        if (A != 0) all0 = false;
    }
    
    cout << (all0 ? "No\n" : "Yes\n");
}