23.10.07

program o;
{$APPTYPE CONSOLE}
var a1,a2,a3,b1,b2,b3,m,k:integer;
a,b:array [1..3] of integer;
begin
assign(input,'input.txt');
reset(input);
assign(output,'output.txt');
rewrite(output);
read(a1,a2,a3,b1,b2,b3);
a[1]:=a1;
a[2]:=a2;
a[3]:=a3;
b[1]:=b1;
b[2]:=b2;
b[3]:=b3;
m:=1;
if a[2] > a[m] then m:=2;
if a[3] > a[m] then m:=3;
k:=a[1];
a[1]:=a[m];
a[m]:=k;
if a[3] > a[2] then
begin
k:=a[2];
a[2]:=a[3];
a[3]:=k;
end;
m:=1;
if b[2] > b[m] then m:=2;
if b[3] > b[m] then m:=3;
k:=b[1];
b[1]:=b[m];
b[m]:=k;
if b[3] > b[2] then
begin
k:=b[2];
b[2]:=b[3];
b[3]:=k;
end;
write((a[1]*b[1])+(a[2]*b[2])+(a[3]*b[3]));
close(output);
end.