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