#include <bits/stdc++.h>
using namespace std;
#define FOR(i, a, b) for(int i = (a); i < (b); i++)
#define RFOR(i, a, b) for(int i = (a) - 1; i >= (b); i--)
#define SZ(a) int(a.size())
#define ALL(a) a.begin(), a.end()
#define PB push_back
#define MP make_pair
#define F first
#define S second
typedef long long LL;
typedef vector<int> VI;
typedef pair<int, int> PII;
typedef double db;
db calc(vector<db> p)
{
db res = 2 * p[0] * p[1] * p[2];
FOR(i, 0, 3)
FOR(j, 0, 3)
if(j != i)
res += p[i] * p[j] * p[j];
return res;
}
int main()
{
ios::sync_with_stdio(0);
cin.tie(0);
cout << fixed << setprecision(10);
cout << calc({0.3333, 0.3333, 0.3333}) << "\n";
cout << calc({0.4641, 0.26795, 0.26795}) << "\n";
0.2962074163
0.2871873108
return 0;
}