//acmp.ru 0685 zolotoy_pesok.cpp 10%

#include <stdio.h>

int main(){
	freopen("INPUT.TXT", "r", stdin);
	freopen("OUTPUT.TXT", "w", stdout);

	int arr1[3], arr2[3];
	scanf("%i %i %i %i %i %i", &arr1[0], &arr1[1], &arr1[2], &arr2[0], &arr2[1], &arr2[2]);

	int maxprice = 0, maxkg = 0, pri, kgi, currentprice = 0;
	for (int j = 0; j < 3; j++){
		for (int i = 0; i < 3; i++){
			if(arr1[i] > maxprice){
				maxprice = arr1[i];
				pri = i;
			}
			if(arr2[i] > maxkg){
				maxkg = arr2[i];
				kgi = i;
			}
		}
		arr1[pri] = 0; 
		arr2[kgi] = 0;
		currentprice = currentprice+(maxkg * maxprice);
		maxkg = 0;
		maxprice = 0;
	}
		printf("%i",currentprice);
}