Program spell; Var a,b,c,d,s1,s2,s3:integer; Begin readln(a,b,c,d); s1:=a * b + c * d; s2:=a * c + b * d; s3:=b * c + a * d; if (s1 > s2) then if (s2 < s3) then write(s1) else if (s1 > s3) then write(s1) else write(s2) else if (s1 > s3) then write(s2) else if (s3 > s2) then write(s3) else write(s2); readln; End.