YSu8YW - Online IDE & Debugging Tool

#include <bits/stdc++.h>

using namespace std;

int main()
{
	ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0); cout.tie(0);

	int t;
	cin >> t;
	while (t--)
	{
		int n, k; cin >> n >> k;
		string f0 = "a" ,f1 = "b", fn;
		for (int i = 2; i <= n; i++)
		{
			fn = f0 + f1;
			f0 = f1;
			f1 = fn;
		}
		if (n == 0)
		{
			cout << f0 << endl;
			continue;
		}
		else if (n == 1)
		{
			cout << f1 << endl;
			continue;
		}
		cout << f1[k - 1] << endl;
	}
}