func_code_string: #include <bits/stdc++.h>   using namespace std;   int a[100000];   int n, k;   int main() {     scanf( %d%d , &n, &k);     for (int i = 0; i < n; i++) scanf( %d , &a[i]);     int l = 0, r = n;     while (r - l > 1) {       int m = (l + r) / 2;       if ((long long)k > (long long)m * (m + 1) / 2)         l = m;       else         r = m;     }     printf( %d , a[k - l * (l + 1) / 2 - 1]);     return 0;   }   