#include <bits/stdc++.h>

using namespace std;

using i64 = long long;

void solve(){
    int n;
    cin >> n;
    vector<int>a(n + 2);
    for (int i = 1;i <= n;i ++){
        cin >> a[i];
    }
    vector<int>s(n + 2);
    for (int i = n;i >= 1;i --){
        s[i] = s[i + 1] + a[i];
        if (s[i] < 0){
            cout << "Yes\n";
            return;
        }
    }
    cout << "No\n";

}       

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

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