#include <bits/stdc++.h>
using namespace std;
string s;char c;int k;
int main()
{
	while(1)
	{
		cin>>c;if(c=='@')break;
		else s+=c;
	}
	for(int i=0;i<s.size();i++)
	{
		if(s[i]=='(')k++;
		if(s[i]==')')k--;
	}if(k==0)cout<<"YES";else cout<<"NO";
    return 0;
}