#include<iostream>
#include<string>
#include<cmath>
using namespace std;

int main()
{
	string s;
	cin >> s;
	long long n;
	cin >> n;
	long long i = n;
	for (int factor = log2(n / s.length()) + 1; factor > 0; factor--)
	{
		if (i == s.length() * pow(2, factor - 1) + 1)
		{
			i = s.length() * pow(2, factor - 1);
		}
		else if (i > s.length() * pow(2, factor - 1) + 1)
		{
			i = i - s.length() * pow(2, factor - 1) - 1;
		}
	}
	cout << s[i - 1];
	return 0;
}

测试点2 输入：ABCDEFGHIJKLMNOPQRSTUVWXYZ 99999999999999999 输出：D