program ex27;

uses
  sysutils;
var
  numbers:array [1..2] of integer;
  loopcounter, loopcounter1, i, loopcounter2, startat, answer, dummy : integer;
  valid: boolean;
  input : string;

procedure getinput;                                          //WORKS
begin
//initialise
  for i := 1 to 2 do
      numbers[i]:= 0;

  for loopcounter:=1 to 2 do
    begin
      repeat
        write('Please enter the number: ');
        readln(input);
        valid:=true;

        if length(input)=0 then
          valid:=false
        else
        begin
          if input[1]='-' then
            startat:=2
          else
            startat:=1;

            for loopcounter2:=startat to length(input) do
              begin
                if not (input[loopcounter2] in ['0'..'9']) then
                  valid:=false;
                  break;
              end;
          end;
        if not valid then
          writeln('this is not a valid integer.');
      until valid;
      numbers[loopcounter1]:=strtoint(input);
    end;
end;
procedure calculatefibonacci(numbers: array of integer);
begin
  for loopcounter:=1 to 2 do
    dummy:=numbers[1]+numbers[2];
  write(numbers[2]);
  begin
      answer:=numbers[1]+numbers[2];
      writeln(answer);
      writeln;
  end;
end;
procedure closeprogram;
begin
write('Press enter to close');
readln;
end;

begin
  getinput;
  calculatefibonacci(numbers);
  closeprogram;
end.