大佬们，小子又来卖萌了！啊~~~

＃include<stdio.h>
int main()
{
int a,b,c,d,e,f,s;
scanf("%d %d %d %d %d %d",&a,&b,&c,&d,&e,&f);
s=(a*b+b*e+b*c*f+e*d+a*f+c*b)*(1/2);
printf("%d",s);
return 0;
}