#include<bits/stdc++.h>
using namespace std;
int main() {
	stack<char> s;
	string s1;
	cin>>s1;
	for(int i=0; i<s1.length(); i++) {
		if(s1[i]=='('||s1[i]=='[') {
			s.push(s1[i]);
		} else if(s1[i]==')') {
			if(s.top()=='(') {
				s.pop();
			} else {
				cout<<"Wrong";
				return 0;
			}
		} else if(s1[i]==']') {
			if(s.top()=='[') {
				s.pop();
			} else {
				cout<<"Wrong";
				return 0;
			}
		}
	}
	cout<<"OK";
	return 0;
}