#include <iostream>
#include <cmath>
#include <vector>
#include <utility>
#include <queue>
#include <map>
#include <string>
#include <cstring>
#include <list>
#include <algorithm>
#define INF 114514
using namespace std;

typedef pair<double,double> P;
typedef long long ll;

int main(void){
	int a;
	map<int,char> dic;
	dic[3] = 'k';
	dic[4] = 'i';
	dic[7] = 'd';
	dic[8] = 'e';

	while(cin >> a,a != 0){
		cout << dic[a] << endl;
	}

	return 0;
}