#include <bits/stdc++.h>
using namespace std;
int main() {
  int i = 0, uk = 0, n, k, c;
  cin >> n >> k;
  cout << endl;
  int str[100000];
  while (i < k) {
    cin >> str[uk];
    uk++;
    i = i + uk;
  }
  c = uk - (i - k + 1);
  cout << endl;
  cout << str[c];
  return 0;
}
