with Ada.Text_IO; use Ada.Text_IO;
procedure Hello is
begin
   Put_Line ('Hello, world!');
end Hello;

with Ada.Text_IO; use Ada.Text_IO;
procedure Show_Num is
   Num : Integer := 10;
begin
   Put_Line (Integer'Image(Num));
end Show_Num;

with Ada.Text_IO; use Ada.Text_IO;
procedure Reverse_Array is
   type Int_Array is array (1 .. 5) of Integer;
   Arr : Int_Array := (1, 2, 3, 4, 5);
   Reversed : Int_Array;
begin
   for I in reverse Arr'Range loop
      Reversed (Arr'First + Arr'Last - I) := Arr (I);
   end loop;
   for I in Arr'Range loop
      Put_Line (Integer'Image(Reversed(I)));
   end loop;
end Reverse_Array;

with Ada.Text_IO; use Ada.Text_IO;
with Ada.Real_Time; use Ada.Real_Time;
procedure Sleep_Example is
   Time : Time_Span := Milliseconds (500);
begin
   delay until Clock + Time;
   Put_Line ('500 milliseconds have passed');
end Sleep_Example;

with Ada.Text_IO; use Ada.Text_IO;
procedure Show_Person is
   type Person is
      record
         Name : String (1 .. 20);
         Age  : Integer;
      end record;
   John : Person := (Name => 'John', Age => 30);
begin
   Put_Line (John.Name & ', ' & Integer'Image(John.Age));
end Show_Person;

with Ada.Text_IO; use Ada.Text_IO;
procedure Show_Sum is
   function Sum (A, B : Integer) return Integer is
   begin
      return A + B;
   end Sum;
   X : Integer := 5;
   Y : Integer := 10;
begin
   Put_Line (Integer'Image(Sum (X, Y)));
end Show_Sum;