17 lines
233 B
C++

#include<iostream>
using namespace std;
char a[255];
int main()
{
int n=0,s=0;
do
{
n++;
cin>>a[n];
if (a[n]=='(') s++;
if (a[n]==')') s--;
}while(a[n]!='@');
if (s==0)cout<<"YES";
else cout<<"NO";
}