#include<stdio.h>

void sort(int *a,int n){
  int i,j;
  for(i=1;i<n;i++){
    int p=a[i];
    j=i-1;
    while(j>=0 && a[j]>p){
      a[j+1]=a[j];
      j--;
    }
    a[j+1]=p;
  }
  return;
}

void run(void){
  int l[3];
  int r[3];
  scanf("%d%d%d",l,l+1,l+2);
  scanf("%d%d%d",r,r+1,r+2);

  sort(l,3);
  sort(r,3);
  int ans=2*(l[0]*(r[2]+r[1])+l[1]*(r[2]+r[0])+l[2]*(r[0]+r[1]));
  printf("%d\n",ans);
  return;
}

int main(void){
  run();
  return 0;
}