#define _CRT_SECURE_NO_WARNINGS
#include <bits/stdc++.h>
#include <unordered_map>
#include <map>
#define ll long long
#define endl '\n'
#define Pi 3.1415926535898
const int N = 2e6 + 5;
#define watch(x) cout << #x << " = " << x << endl;
#define all(v) (v).begin(),(v).end()
using namespace std;
// cout << fixed << setprecision(9);
void fast() {
	std::ios_base::sync_with_stdio(0);
	cin.tie(NULL);
	cout.tie(NULL);
}
void file() {
#ifndef ONLINE_JUDGE
	freopen("in.txt", "r", stdin);
	freopen("out.txt", "w", stdout);
#endif
}
int dx[] = { 0, 0, 1, -1, 1, -1, 1, -1 }; // dir array
int dy[] = { 1, -1, 0, 0, 1, -1, -1, 1 };

int main() {
	fast();
	file();
	int t;
	cin >> t;
	map <string, int > mp;
	while (t--) {
		string s;
		cin >> s;
		if (mp[s] == 0) {
			cout << "ok" << endl;
			mp[s] ++;
		}
		else {
		    int c = 0 ; 
            for (auto it : mp ){
                c++ ; 
                char ch = (c+'0');
                string t= s + ch ; 
                if (mp[t] == 0){
                    break; 
                }
            }
            mp[s] = c ; 
            char x= mp[s] + '0' ; 
            string str = s+x ; 
            cout << str<< endl ;
            mp[str] ++ ;
            
		}
	}
	return 0;
}