Программа + - * / чисел

Program One;
Var a,b,c,d, k: byte;
Begin
WriteLn ( 'Vvedite 4 chisla' );
ReadLn (a);
ReadLn (b);
ReadLn (c);
ReadLn (d);
k:=a+b+c+d;
WriteLn ('Summa chisel=', k)
ReadLn;
End.

Program Two;
var a,b,c,d: byte;
var k: integer;
begin
WriteLn ('Vvedite 4 chisla');
ReadLn (a);
ReadLn (b);
ReadLn (c);
ReadLn (d);
k:=a-b-c-d;
WriteLn ('Raznost chisel=', k)
ReadLn;
End.

Program ; Three
var a,b,c,d:integer;
var k: real;
begin
WriteLn ('Vvedite 4 chisla');
ReadLn (a);
ReadLn (b);
ReadLn (c)
ReadLn (d)
k:=a*b*c*d;
WriteLn ('Proizvedenie chisel=', k)
ReadLn;
End.

Program ; Four
var a,b,c,d:integer;
var k:real;
begin
WriteLn ('Vvedite 4 chisla');
ReadLn (a);
ReadLn (b);
ReadLn (c)
ReadLn (d)
c:=a/b/с/d;
WriteLn (Chastnoe chisel=',c)
ReadLn;
End.