691A - Fashion in Berland - CodeForces Solution

#include <bits/stdc++.h>
using namespace std;
# define ll long long int
#define cn cout<<"NO"<<endl
#define cy cout<<"YES"<<endl
#define pb push_back

int main() {
    ll n;
    cin>>n;
    ll ct0=0;
    for(int i=0;i<n;i++) {
      ll x;
      cin>>x;
      if(x==0){
        ct0++;
      }
    }
    if(n==1&&ct0==0){
      cy;
    }
    else if(n>1&&ct0==1){
      cy;
    }
    else {
      cn;
    }
    return 0;
}