#include <bits/stdc++.h>
#define rep(i,n) for(int i = 0; i < (int)(n); i++)
#define rrep(ri,n) for(int ri = (int)(n-1); ri >= 0; ri--)
#define rep2(i,x,n) for(int i = (int)(x); i < (int)(n); i++)
#define rrep2(ri,x,n) for(int ri = (int)(n-1); ri >= (int)(x); ri--)
#define repit(itr,x) for(auto itr = x.begin(); itr != x.end(); itr++)
#define rrepit(ritr,x) for(auto ritr = x.rbegin(); ritr != x.rend(); ritr++)
#define ALL(x) x.begin(), x.end()
using ll = long long;
using namespace std;

void fc(long double p, long double q, long double r, long double &ans){
  long double add = p;
  ans = max(ans, add);
  add = (1-p);
  ans = max(ans, add);
}

int main(){
  int ip, iq, ir;
  cin >> ip >> iq >> ir;
  int s = ip + iq + ir;
  long double p = (long double)ip/s;
  long double q = (long double)iq/s;
  long double r = (long double)ir/s;
  long double ans = 0;
  fc(p, q, r, ans);
  fc(q, r, p, ans);
  fc(r, p, q, ans);
  cout << fixed << setprecision(10) << ans << endl;
  return 0;
}