#define ll long long
#define fr first
#define sc second
#define pb(x) push_back(x)
#define el '\n'
#define sz(container) ((ll) container.size())

#include <bits/stdc++.h>
using namespace std;

int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(nullptr);
  cout.tie(nullptr);

  ll n, i;
  string s, t;
  unordered_map<string, ll> mp;
  bool b;

  cin >> n;
  
  while (n--) {
    cin >> s;

    if (mp[s]) {
      b = 1;
      for (;b; ++mp[s]) {
        t = s + to_string(mp[s]);
        if (!mp[t]) {
          cout << t << el;
          mp[t] = 1;
          b = 0;
        }
      }
      
    } else {
      cout << "ok\n";
      mp[s] = 1;
    }
  }


  return 0;
}