tj

#include<bits/stdc++.h>
#include<stack>
using namespace std;
stack<char>st;
int main()
{
 	char s;
 	while(cin>>s)
 	{
 		if(s == '@') break;
 		else if(s == '(') st.push(s);
 		else if(s == ')')
 		{
 			if(!st.empty()) st.pop();
			else
			{
				cout<<"NO";
				return 0;
			}	
		}
	}
	if(!st.empty()) cout<<"NO";
	else cout<<"YES";
	return 0;
}