#include <bits/stdc++.h>
using namespace std;
int main () {
	char s[2600];
	stack<bool>a;
	cin >> s;
	bool flag = true;
	for (int i = 0; s[i] != '@'; i++) {
		if (s[i] == '(') {
			a.push(true);
		} else if (s[i] == ')') {
			if (a.empty()) {
				flag = false;
			}
			a.pop();
		}
	}
	if (!a.empty()) {
		flag = false;
	}

	printf("%s\n", flag ? "YES" : "NO");
	return 0;
}