#include<bits/stdc++.h>
#define int long long
using namespace std;
int len; 
string s;
stack<char>sta;
signed main()
{
    freopen("check.in","r",stdin);
    freopen("check.out","w",stdout);
    cin>>s;
    len=s.size();
    for(int i=0;i<len;i++)
    {
        if(s[i]=='('||s[i]=='[') sta.push(s[i]);
        else if(s[i]==')')
        {
            if(sta.size()&&sta.top()=='(') sta.pop();
            else sta.push(s[i]);
        }
        else
        {
            if(sta.size()&&sta.top()=='[') sta.pop();
            else sta.push(s[i]);
        }
    }
    if(sta.empty()) printf("OK");
    else printf("Wrong");
    return 0;
}