Var Max, a, b, c, d: Real;
BEGIN
Writeln ('Nhap gia tri cua 4 so: ');
Write ('a = ') ; Readln (a);
Write ('b = ') ; Readln (b);
Write ('c = ') ; Readln (c);
Write ('d = ') ; Readln (d);
Max:= a;
If Max < b Then Max:= b;
If Max < c Then Max:= c;
If Max < d Then Max:= d;
Writeln ('Gia tri lon nhat la: ', Max);
Readln;
END