#include <bits/stdc++.h>
#define MOD 998244353
#define mod 1000000007
using namespace std;
int main()
{
	string s;
	cin >> s;
	int left = 0,right = 0;
	for (int i = 0; i < s.length(); i++)
	{
	    if (s[i] == '(') left++;
	    if (s[i] == ')') right++;
	    if (s[i] == '@') break;  
    }
    left == right ? cout << "YES\n" : cout << "NO\n";
	return 0;
}