func_code_string: #include <bits/stdc++.h>   using namespace std;   int n, a, b;   int main() {     cin >> n >> a >> b;     long long chores[n];     for (int i = 0; i < n; i++) cin >> chores[i];     sort(chores, chores + n);     cout << chores[b] - chores[b - 1] << endl;     return 0;   }   