#include <iostream>
#include <stack>
#include <string>
using namespace std;
 
int main()
{
	string str;
 
	while (1)
	{
		stack<char> st;
		getline(cin, str);
		if (str[0] == '.')
			return 0;
 
		if (str[0] == '.')
		{
			break;
		}
		for (int i = 0; i < str.length(); i++)
		{
			if (str[i] == '(' || str[i] == '[')
				st.push(str[i]);
 
			else if (str[i] == ')')
			{
				if (st.top() != '(' || st.empty())
				{
					cout << "NO" << endl;
					break;
				}
				else
					st.pop();
			}
			else if (str[i] == ']')
			{
				if (st.top() != '[' || st.empty())
				{
					cout << "NO" << endl;
				break;
				}
				else
					st.pop();
			}
		}
		if (st.empty())
			cout << "YES" << endl;
		else
			cout << "NO" << endl;
	}
	return 0;
}

I2luY2x1ZGUgPGlvc3RyZWFtPgojaW5jbHVkZSA8c3RhY2s+CiNpbmNsdWRlIDxzdHJpbmc+CnVzaW5nIG5hbWVzcGFjZSBzdGQ7CgppbnQgbWFpbigpCnsKCXN0cmluZyBzdHI7CgoJd2hpbGUgKDEpCgl7CgkJc3RhY2s8Y2hhcj4gc3Q7CgkJZ2V0bGluZShjaW4sIHN0cik7CgkJaWYgKHN0clswXSA9PSAnLicpCgkJCXJldHVybiAwOwoJCQoJCWlmIChzdHJbMF0gPT0gJy4nKQoJCXsKCQkJYnJlYWs7CgkJfQoJCWZvciAoaW50IGkgPSAwOyBpIDwgc3RyLmxlbmd0aCgpOyBpKyspCgkJewoJCQlpZiAoc3RyW2ldID09ICcoJyB8fCBzdHJbaV0gPT0gJ1snKQoJCQkJc3QucHVzaChzdHJbaV0pOwoKCQkJZWxzZSBpZiAoc3RyW2ldID09ICcpJykKCQkJewoJCQkJaWYgKHN0LnRvcCgpICE9ICcoJyB8fCBzdC5lbXB0eSgpKQoJCQkJewoJCQkJCWNvdXQgPDwgIk5PIiA8PCBlbmRsOwoJCQkJCWJyZWFrOwoJCQkJfQoJCQkJZWxzZQoJCQkJCXN0LnBvcCgpOwoJCQl9CgkJCWVsc2UgaWYgKHN0cltpXSA9PSAnXScpCgkJCXsKCQkJCWlmIChzdC50b3AoKSAhPSAnWycgfHwgc3QuZW1wdHkoKSkKCQkJCXsKCQkJCQljb3V0IDw8ICJOTyIgPDwgZW5kbDsKCQkJCWJyZWFrOwoJCQkJfQoJCQkJZWxzZQoJCQkJCXN0LnBvcCgpOwoJCQl9CgkJfQoJCWlmIChzdC5lbXB0eSgpKQoJCQljb3V0IDw8ICJZRVMiIDw8IGVuZGw7CgkJZWxzZQoJCQljb3V0IDw8ICJOTyIgPDwgZW5kbDsKCX0KCXJldHVybiAwOwp9

U28gd2hlbiBJIGRpZSAodGhlIFtmaXJzdF0gSSB3aWxsIHNlZSBpbiAoaGVhdmVuKSBpcyBhIHNjb3JlIGxpc3QpLgpbIGZpcnN0IGluIF0gKCBmaXJzdCBvdXQgKS4KSGFsZiBNb29uIHRvbmlnaHQgKEF0IGxlYXN0IGl0IGlzIGJldHRlciB0aGFuIG5vIE1vb24gYXQgYWxsXS4KQSByb3BlIG1heSBmb3JtICkoIGEgdHJhaWwgaW4gYSBtYXplLgpIZWxwKCBJW20gYmVpbmcgaGVsZCBwcmlzb25lciBpbiBhIGZvcnR1bmUgY29va2llIGZhY3RvcnkpXS4KKFsgKChbKCBbIF0gKSAoICkgKCggKSldICkpIF0pLgogLgou

So when I die (the [first] I will see in (heaven) is a score list).
[ first in ] ( first out ).
Half Moon tonight (At least it is better than no Moon at all].
A rope may form )( a trail in a maze.
Help( I[m being held prisoner in a fortune cookie factory)].
([ (([( [ ] ) ( ) (( ))] )) ]).
 .
.