#include<bits/stdc++.h>
using namespace std;
string a,s;
int top=0;
int main()
{
	cin>>a;
	for(int i=0;i<a.size();i++){
		if(a[i]=='('||a[i]=='['){
			s[++top]=a[i];
		}
		else if(a[i]==')'&&s[top]=='('&&top>0){
			top--;
		}else if(a[i]==']'&&s[top]=='['&&top>0){
			top--;
		}else{
			cout<<"no";
			return 0;
		}
	}
	if(top==0){
		cout<<"yes";
	}else{
		cout<<"no";
	}
	return 0;
}