program lon_nhat;

uses crt;

var a,b,c,d,ln:integer;

{---ham-2-so---}

function max(x,y:integer):integer;

begin

       if x>y then max:x else max:=y;

end;

{---Chuong-trinh-chinh---}

BEGIN

       clrscr;

       write('Nhap so thu nhat: ');  readln(a);

       write('Nhap so thu hai: ');  readln(b);

       write('Nhap so thu ba: ');  readln(c);

       write('Nhap so thu tu: ');  readln(d);

       ln:=max(a,b);

       ln:=max(ln,c);

       ln:=max(ln,d);

       write('So lon nhat la: ',ln);

       readln;

end.

uses crt;
var a,b,c,d,sln:longint;
//Ham tim so lon nhat trong 2 so
Function max(a,b:longint):longint;
   begin
      max:=a;
      if b>a then max:=b;
   end;
begin
clrscr;
   write('Nhap so thu nhat:');readln(a); 
   write('Nhap so thu hai:');readln(b); 
   write('Nhap so thu ba:');readln(c); 
   write('Nhap so thu bon:');readln(d); 
   sln:=max(a,max(b,max(c,d)));
   writeln('So lon nhat trong 4 so: ',sln);
readln
end.