#include <bits/stdc++.h>
#define ll long long
#define pb push_back
#define mp make_pair
#define FAST ios_base::sync_with_stdio(0),cin.tie(0),cout.tie(0);
#define INF INT_MAX
#define ff first
#define ss second
#define all(v) v.begin(),v.end()
#define nl "\n"
using namespace std;
const ll MOD  = 1e9+7;
const int mxN = 2e5+1;

int main()
{
    FAST
    //==================
    map<string,int> m;
    ll n; cin >> n;
    for(int i=0;i<n;i++){
        string s; cin >> s;
        if(m[s] == 0){
            cout << "ok\n";
            m[s]++;
        }else{
            string k = s + to_string(m[s]);
            while(m[k]!=0){
                k = s + to_string(m[s]);
                m[s]++;
            }
            m[k]++;
            cout << k << nl;
        }
    }




}