#include <stdio.h>
#include <atcoder/all>
#include <bits/stdc++.h>
using namespace std;
using namespace atcoder;
using mint = modint998244353;
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define Inf32 1000000005
#define Inf64 1000000000000000001LL

int main(){
	
	int n;
	cin>>n;
	vector<int> a(n);
	rep(i,n)cin>>a[i];
	if(a==vector<int>(n,0))cout<<"No"<<endl;
	else cout<<"Yes"<<endl;
	return 0;
}