/*ver 7*/
#include <bits/stdc++.h>
using namespace std;
void init() {cin.tie(0);ios::sync_with_stdio(false);cout << fixed << setprecision(15);}
using ll = long long;
using ld = long double;
using vl = vector<ll>;
using vd = vector<ld>;
using vs = vector<string>;
using vb = vector<bool>;
using vvl = vector<vector<ll>>;
using vvd = vector<vector<ld>>;
using vvs = vector<vector<string>>;
using vvb = vector<vector<bool>>;
using pll = pair<ll,ll>;
using mll = map<ll,ll>;
template<class T> using V = vector<T>;
template<class T> using VV = vector<vector<T>>;
#define each(x,v) for(auto& x : v)
#define reps(i,a,b) for(ll i=(ll)a;i<(ll)b;i++)
#define rep(i,n) for(ll i=0;i<(ll)n;i++)
#define pb push_back
#define eb emplace_back
#define fi first
#define se second
#define mp make_pair
const ll INF = 1LL << 60;
#define CLR(mat,f) memset(mat, f, sizeof(mat))
#define IN(a, b, x) (a<=x&&x<=b)
#define UNIQUE(v) v.erase( unique(v.begin(), v.end()), v.end() ) //被り削除
#define debug cout << "line : " << __LINE__ << " debug" << endl;
#define ini(...) int __VA_ARGS__; in(__VA_ARGS__)
#define inl(...) long long __VA_ARGS__; in(__VA_ARGS__)
#define ind(...) long double __VA_ARGS__; in(__VA_ARGS__)
#define ins(...) string __VA_ARGS__; in(__VA_ARGS__)
#define inc(...) char __VA_ARGS__; in(__VA_ARGS__)
void in(){}
template <typename T,class... U> void in(T &t,U &...u){ cin >> t; in(u...);}
template <typename T> void in1(T &s) {rep(i,s.size()){in(s[i]);}}
template <typename T> void in2(T &s,T &t) {rep(i,s.size()){in(s[i],t[i]);}}
template <typename T> void in3(T &s,T &t,T &u) {rep(i,s.size()){in(s[i],t[i],u[i]);}}
template <typename T> void in4(T &s,T &t,T &u,T &v) {rep(i,s.size()){in(s[i],t[i],u[i],v[i]);}}
template <typename T> void in5(T &s,T &t,T &u,T &v,T &w) {rep(i,s.size()){in(s[i],t[i],u[i],v[i],w[i]);}}
void out(){cout << endl;}
template <typename T,class... U> void out(const T &t,const U &...u){cout << t; if(sizeof...(u)) cout << " "; out(u...);}
void die(){cout << endl;exit(0);}
template <typename T,class... U> void die(const T &t,const U &...u){cout << t; if(sizeof...(u)) cout << " "; die(u...);}
template <typename T> void outv(T s) {rep(i,s.size()){if(i!=0)cout<<" ";cout<<s[i];}cout<<endl;}
template <typename T> void out1(T s) {rep(i,s.size()){out(s[i]);}}
template <typename T> void out2(T s,T t) {rep(i,s.size()){out(s[i],t[i]);}}
template <typename T> void out3(T s,T t,T u) {rep(i,s.size()){out(s[i],t[i],u[i]);}}
template <typename T> void out4(T s,T t,T u,T v) {rep(i,s.size()){out(s[i],t[i],u[i],v[i]);}}
template <typename T> void out5(T s,T t,T u,T v,T w) {rep(i,s.size()){out(s[i],t[i],u[i],v[i],w[i]);}}
#define all(v) (v).begin(),(v).end()
#define rall(v) (v).rbegin(),(v).rend()
template <typename T> T allSum(vector<T> a){T ans=T();each(it,a)ans+=it;return ans;}
ll ceilDiv(ll a,ll b) {return (a+b-1)/b;}
ld dist(pair<ld,ld> a, pair<ld,ld> b){return sqrt(abs(a.fi-b.fi)*abs(a.fi-b.fi)+abs(a.se-b.se)*abs(a.se-b.se));} // ２点間の距離 
ll gcd(ll a, ll b) { return b != 0 ? gcd(b, a % b) : a; }
ll lcm(ll a,ll b){ return a / gcd(a,b) * b;}
template <class A, class B> inline bool chmax(A &a, const B &b) { return b > a && (a = b, true); }
template <class A, class B> inline bool chmin(A &a, const B &b) { return b < a && (a = b, true); }
#define YES(n) ((n) ? "YES" : "NO"  )
#define Yes(n) ((n) ? "Yes" : "No"  )
#define yes(n) ((n) ? "yes" : "no"  )


int main(){
	init();
	inl(a,b,c);
	V<ll> d{a,b,c};
	map<V<ll>,ld> memo;
	memo[d]=1;
	deque<V<ll>> q;
	ld ans=0;
	q.push_back(d);
	while(q.size()!=0){
		V<ll> now=q.front();
		q.pop_front();
		if(now[0]==100 ||now[1]==100 ||now[2]==100){
			ans+=(now[0]+now[1]+now[2]-d[0]-d[1]-d[2])*memo[now];
			continue;
		}
		ll sum=now[0]+now[1]+now[2];
		rep(i,3){
			if(now[i]!=0){	
				V<ll> next=now;
				next[i]++;
				if(memo.count(next)==0){
					q.push_back(next);
					memo[next]=0;
				}
				memo[next]+=memo[now]*now[i]/sum;
			}
		}
	}
	out(ans);
	return 0;
}
#include <iostream>
#include <iomanip>

double dp[101][101][101];

double dfs(int a, int b, int c){
   if(dp[a][b][c]) return dp[a][b][c];
   if(a==100 || b==100 || c==100) return 0;

   double ret = (dfs(a+1, b, c) + 1) * a / (a+b+c);
   ret += (dfs(a, b+1, c) + 1) * b / (a+b+c);
   ret += (dfs(a, b, c+1) + 1) * c / (a+b+c);
   dp[a][b][c] = ret;

   return ret;
}

int main(){
   int A, B, C;
   std::cin >> A >> B >> C;

   std::cout << std::fixed << std::setprecision(10) <<  dfs(A, B, C) << std::endl;

   return 0;
}
