#include <bits/stdc++.h>

using namespace std;

#define FOR(i, a, b) for(int i = (a); i < (b); i++)
#define RFOR(i, a, b) for(int i = (a) - 1; i >= (b); i--)
#define SZ(a) int(a.size())
#define ALL(a) a.begin(), a.end()
#define PB push_back
#define MP make_pair
#define F first
#define S second

typedef long long LL;
typedef vector<int> VI;
typedef pair<int, int> PII;
typedef long double db;

const LL INF = 1'000'000;
const LL LINF = INF * INF;

int main()
{
	ios::sync_with_stdio(0); 
	cin.tie(0);
	cout << fixed << setprecision(15);
	
	int n;
	cin >> n;
	
	vector<string> v;
	FOR (i, 0, 26)
	{
		FOR (j, 0, 26)
		{
			FOR (k, 0, 26)
			{
				string s = "";
				s += 'a' + i;
				s += 'a' + j;
				s += 'a' + k;
				v.PB(s);
			}
		}
	}
	
	int idx = 0;
	
	map<LL, string> m;
	FOR (i, 0, n)
	{
		db d;
		cin >> d;
		char c;
		cin >> c;
		LL x = d * LINF;
		if (m.count(x))
			cout << m[x] << '\n';
		else
		{
			cout << v[idx] << '\n';
			m[x] = v[idx];
			idx++;
		}
	}
	
	
	return 0;
}