#include <bits/stdc++.h>   using namespace std;   long long n, n1, n2, a[111111], sum1 = 0, sum2 = 0;   int main() {     cin >> n >> n1 >> n2;     for (int i = 0; i < n; i++) cin >> a[i];     if (n1 > n2) swap(n1, n2);     sort(a, a + n);     reverse(a, a + n);     int i = 0;     int m1 = n1;     int m2 = n2;     while (m1 != 0) {       sum1 += a[i];       i++;       m1--;     }     while (m2 != 0) {       sum2 += a[i];       i++;       m2--;     }     cout << fixed << setprecision(7) << (sum1 * 1.0 / n1) + (sum2 * 1.0 / n2);   }   