#include<iostream>

using namespace std;

#define N 20

char a[256];

bool judge(char c[])
{
    int top=0,i=0;
    while(c[i]!='@')
    {
        if(c[i]=='(')
        {
            top++;
        }
        if(c[i]==')')
        {
            top--;
        }
        i++;
    }
    if(top!=0) 
       return 0;
    else
    {
        return 1;
    }
}

int main()
{
    cin>>a;
    if(judge(a))
    {
        cout<<"YES"<<endl;
    }
    else{
        cout<<"NO"<<endl;
    }
    return 0;
}