#include <bits/stdc++.h>   using namespace std;   double a[100010], ans1, ans2;   int n, n1, n2;   bool cmp(double a, double b) { return a > b; }   int main() {     scanf( %d%d%d , &n, &n1, &n2);     if (n1 > n2) swap(n1, n2);     for (int i = 1; i <= n; i++) scanf( %lf , &a[i]);     sort(a + 1, a + n + 1, cmp);     for (int i = 1; i <= n1; i++) ans1 += a[i];     for (int i = n1 + 1; i <= n1 + n2; i++) ans2 += a[i];     printf( %.8f n , ans1 / n1 + ans2 / n2);     return 0;   }   