#define _CRT_SECURE_NO_WARNINGS 1
#include<iostream>
#include<string>
using namespace std;
string a;
long Left = 0, Right = 0, l1 = -1, r1 = -1, g;
long alen;
int main() {
	getline(cin, a);
	alen = a.size();
	for (long i = 0; a[i] != '@'; i++) {
		if (a[i] == '(') {
			Left++;
			if(l1==-1)l1 = i;
		}
		else if (a[i] == ')') {
			Right++;
			if(r1==-1)r1 = i;
		}
	}
	if (Left != Right || r1 < l1)printf("NO");
	else printf("YES");
	return 0;
}