#include <bits/stdc++.h>
using namespace std;
#define rep(i,n) for(int i = 0; i < (n);i++)
#define sz(x) int(x.size())
typedef long long ll;
typedef long double ld;
typedef pair<int,int> P;

int main() {
  vector<ld> v(3), p(3);
  rep(i,3) cin >> v[i];
  rep(i,3) {
    p[i] = v[i] / (v[0] + v[1] + v[2]);
  }
  sort(p.begin(), p.end());
  printf("%.12Lf\n", p[1] + p[2]);
  return 0; 
}