var
a,b,c,s: longint;
begin
 readln(a,b,c);
 if (a > b) or (a > c) then
   if (b > c) then s:= c - a * b
    else
      s:= b - a * c;
 if (b > a) or (b > c) then
   if a > c then s:= c - a * b
    else
    s:= a - b * c;
  if (c > a) or (c > b) then
   if a > b then s:= b - a * c
    else
     s:=a - b * c;
 writeln(s);
end.