#include <cmath>
#include <iostream>
#include <vector>

using namespace std;

const int oo = 0x3f3f3f3f;
const double eps = 1e-9;
const double PI = 2.0 * acos(0.0);


typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> pii;
typedef vector<int> vi;
typedef vector<string> vs;

#define sz(c) int((c).size())
#define all(c) (c).begin(), (c).end()
#define FOR(i,a,b) for (int i = (a); i < (b); i++)
#define FORS(i,a,b,s) for (int i = (a); i < (b); i=i+(s))
#define FORD(i,a,b) for (int i = int(b)-1; i >= (a); i--)
#define FORIT(i,c) for (__typeof__((c).begin()) i = (c).begin(); i != (c).end(); i++)


int main(){
	ll a,b,c; cin >> a >> b >> c;

	bool bought = false;
	ll atMostWorse = 0;
	while (1){
		string s; cin >> s;
		if (s == "end") return 0;

		if (bought){cout << "self" << endl; continue;}

		// decide if we should buy
		atMostWorse += (a-c);
		if (atMostWorse >= b){
			cout << "buy" << endl;
			bought = true;
			continue;
		}

		cout << "airline" << endl;
	}
}