func_code_string: #include <bits/stdc++.h>   using namespace std;   const int MOD = 1e9 + 7;   int a[2020];   void solve() {     int n, x, y;     cin >> n >> x >> y;     for (int i = 0; i < n; i++) cin >> a[i];     sort(a, a + n);     reverse(a, a + n);     int c = 0;     cout << a[x - 1] - a[x];   }   int main() {     ios::sync_with_stdio(false);     cin.tie(0);     int T = 1;     while (T--) solve();   }   