#include <bits/stdc++.h>
using namespace std;
const double pi = acos(-1.0);
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  int n, k;
  cin >> n >> k;
  int count = 1;
  while (k > count) {
    k -= count;
    count++;
  }
  int v;
  for (int i = 0; i < k; i++) {
    cin >> v;
  }
  cout << v;
  return 0;
}
