#include <iostream>
#include <algorithm>
using namespace std;
int main(){
int a1, a2, a3, b1, b2, b3, result = 0;
cin >> a1 >> a2 >> a3 >> b1 >> b2 >> b3;
result += max({a1, a2, a3}) * max({b1, b2, b3});
result += min({a1, a2, a3}) * min({b1, b2, b3});
if(a1 > a2 and a1 > a3) a1 = 0;
else if(a2 > a1 and a2 > a3) a2 = 0;
else if(a3 > a1 and a3 > a2) a3 = 0;
if(b1 > b2 and b1 > b3) b1 = 0;
else if(b2 > b1 and b2 > b3) b2 = 0;
else if(b3 > b1 and b3 > b2) b3 = 0;
result += max({a1, a2, a3}) * max({b1, b2, b3});
cout << result;
}
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