#include <iostream>
#include <string>
#include <unordered_map>
using namespace std;

void increment(string &key){
  for (int i=key.size(); i--;){
    if (key[i]!='z') {++key[i];break;}
    key[i]='a';
  }
}

int main(){
  int n; cin>>n;
  unordered_map<string,string> have;
  string key="aaaa";
  while (n--){
    string s; cin>>s;
    s.pop_back();
    if (s.find('.')!=string::npos){
      while (s.back()=='0') s.pop_back();
      if (s.back()=='.') s.pop_back();
    }
    if (not have.count(s)){
      have[s]=key;
      increment(key);
    }
    cout<<have[s]<<endl;
  }
  return 0;
}