#include <bits/stdc++.h>
using namespace std;

map<char, char> mp = {{')', '('}, {']', '['}};
int main() {
    stack<char> sk;
    string s;
    cin>>s;
    for(auto c : s) {
        if(c == '(' || c == '[') sk.push(c);
        else {
            if(!sk.empty() && sk.top() == mp[c])
                sk.pop();
            else {
                cout<<"Wrong";
                return 0;
            }
        }
    }
    if(sk.empty()) cout<<"OK";
    else cout<<"Wrong";
    return 0;
}