a,b,c,i;main(f,e,d){scanf("%d",&f);e>f?f^=e^=f^=e:0;d>e?d^=e^=d^=e:0;++i>5?a=!printf("%d",a*f+b*e+c*d<<1):i==3?a=d+e,b=d+f,c=e+f,main(0,0,0):main(0,f,e);}