#include <bits/stdc++.h>
using namespace std;
const int inf = 0x3f3f3f3f;
const int N = 100000 + 10;
const int M = N * N;
int A[N];
int main() {
  int n, k;
  cin >> n >> k;
  for (int i = 1; i <= n; ++i) cin >> A[i];
  for (int i = 1; i <= n; ++i) {
    if (k > i) {
      k -= i;
      continue;
    }
    cout << A[k] << endl;
    break;
  }
  return 0;
}
