main(y,z){int a[z=12];for(;z--;)scanf("%d",a+z);for(z=9;z--;)a[z]-=a[9+z%3];printf("%d",(a[7]*(a[3]*a[2]-*a*a[5])+a[6]*(a[1]*a[5]-a[4]*a[2])+a[8]*(*a*a[4]-a[3]*a[1]))/6);}