/*
Author : Shohanur Rahaman
*/
 
#include<stack>
#include<cstdio>
#include<iostream>
#include<string>
using namespace std;
 
bool checkMatch(char open,char close)
{
    if(open == '(' && close == ')') return true;
    else if(open == '{' && close == '}') return true;
    else if(open == '[' && close == ']' ) return true;
    else false;
}
 
bool checkBalance(string str)
{
    stack <char> mystack;
 
    for(int i=0;i<str.length();i++){
            if(str[i] == '(' || str[i] == '{' || str[i] == '['){
                mystack.push(str[i]);
            }
            else if(str[i]==')' || str[i]=='}' || str[i] == ']'){
                    if(mystack.empty() || !checkMatch(mystack.top(),str[i]))
                        return false;
                    else
                        mystack.pop();
            }
    }
        if(mystack.empty() == true)
            return true;
         else
            return false;
 
}
 
int main()
{
    string exp;
 
    while(cin>>exp){
 
        if(checkBalance(exp)){
              cout<<"correct"<<endl;
        }
        else
            cout<<"incorrect"<<endl;
    }
 
 
    return 0;
}