#include <iostream>
using namespace std;

int fib[45];

char solve(int n, int k) {
	if (n == 0) return 'a';
	if (n == 1) return 'b';
	if (k <= fib[n - 2]) return solve(n - 2, k);
	return solve(n - 1, k - fib[n - 2]);
}

int main() {
	int n, k, tests;
	fib[0] = 1;
	fib[1] = 1;
	for (int i = 2; i < 45; i++) fib[i] = fib[i - 1] + fib[i - 2];
	cin >> tests;
	while (tests--) {
		cin >> n >> k;
		cout << solve(n, k) << endl;
	}
	return 0;
}