#include<bits/stdc++.h>
////#include "cmake-build-debug/Car.h"
using namespace std;
#define endl         '\n'
#define ll           long long
const int N = 2e5 + 5 ;
void fast() {
    std::ios_base::sync_with_stdio(0);
    cin.tie(NULL);
#ifndef ONLINE_JUDGE
    freopen("Input.txt", "r", stdin);
    freopen("Output.txt", "w", stdout);
#endif
}
ll gcd(ll a, ll b) {
    return b == 0 ? a : gcd(b, a % b);
}
int lcm(int a, int b) {
    return a / gcd(a, b) * b;
}
int main() {
    fast() ;
    int t;
    cin>>t ;
    map<string,int>mp ;
   // map<string , vector<int>>reg ;
    while (t--)
    {
        string x ;
        cin>>x ;
        if (mp[x] == 0 )
        {
            cout << "ok\n" ;
            mp[x] ++ ;
            reg[x].push_back(1) ;
        }
        else {
            for (int i=1  ;i <=20 ;i++)
            {
                string temp = x ;
                string cur = to_string (i) ;
                temp += cur ;
                if (mp[temp] == 0 )
                {
                    cout << temp << endl ;
                    mp[temp]++;
                    break ;
                }
            }
        }
    }
    return  0 ;
}