#include<bits/stdc++.h>
using namespace std;
const int N = 1e3 + 10 ;
char st[N] ;
int TOP = 0 ;
int main(){
	cin>>st;
	int len = strlen(st);/*
		for (int i = 0 ; i < len ; ++i){
			cout<<st[i];
		}*/
	for (int i = 0 ; i < len ; ++i){
			if (st[i] == '@'){
				break;
			}
			if (st[i] == '('){
				++TOP;
			}
			if (st[i] == ')'){
				--TOP;
			}
	}
	if (TOP != 0){
		cout<<"NO";
	}
	else{
		cout<<"YES";
	}
	return 0 ;
}