Program BinaryDenaryAdder;

{$mode objfpc}{$H+}

Uses
  {$IFDEF UNIX}{$IFDEF UseCThreads}
  cthreads,
  {$ENDIF}{$ENDIF}
  Classes, SysUtils
  { add your units here };

Function AddBinary(BinaryNum1, BinaryNum2 : String) : String;
  Var
    NumberOfDigits, i, Diff : Integer;
    Carry : Char;
    BinaryResult : String;
  Begin
    If Not (Length(BinaryNum1) = Length(BinaryNum2))
      Then
        If Length(BinaryNum1) > Length(BinaryNum2)
          Then
            Begin
              NumberOfDigits := Length(BinaryNum1);
              Diff := NumberOfDigits - Length(BinaryNum2);
              For i := 1 To Diff
                Do BinaryNum2 := '0' + BinaryNum2;
            End
          Else
            Begin
              NumberOfDigits := Length(BinaryNum2);
              Diff := NumberOfDigits - Length(BinaryNum1);
              For i := 1 To Diff
                Do BinaryNum1 := '0' + BinaryNum1;
            End
      Else NumberOfDigits := Length(BinaryNum1);
    Writeln('Binary number input 1: ', BinaryNum1);
    Writeln('Binary number input 2: ', BinaryNum2);
    BinaryResult := '';
    For i := 1 To NumberOfDigits
      Do BinaryResult := BinaryResult + ' ';
    Carry := '0';
    For i := NumberOfDigits DownTo 1
      Do
        If Carry = '0'
          Then
            If (BinaryNum1[i] = '1') And (BinaryNum2[i] = '1')
              Then
                Begin
                  Carry := '1';
                  BinaryResult[i] := '0'
                End
            Else
              If (BinaryNum1[i] = '0') And (BinaryNum2[i] = '0')
                Then BinaryResult[i] := '0'
                Else BinaryResult[i] := '1'
        Else
          If (BinaryNum1[i] = '0') And (BinaryNum2[i] = '0')
            Then
              Begin
                BinaryResult[i] := '1';
                Carry := '0';
              End
            Else
              If (BinaryNum1[i] = '1') And (BinaryNum2[i] = '1')
                Then BinaryResult[i] := '1'
                Else BinaryResult[i] := '0';
    If Carry = '1'
      Then BinaryResult := '1' + BinaryResult;
    AddBinary := BinaryResult;
  End;

Function ConvertDenaryToBinary(DenaryNum : Integer) : String;
  Var
    TempResult, BinaryResult : String;
    Count : Integer;
  Begin
    TempResult := '';
    Repeat
      TempResult := TempResult + IntToStr(DenaryNum Mod 2);
      DenaryNum := DenaryNum Div 2;
    Until DenaryNum = 0;
    BinaryResult := '';
    For Count := Length(TempResult) DownTo 1
      Do BinaryResult := BinaryResult + TempResult[Count];
    ConvertDenaryToBinary := BinaryResult;
  End;

Var
  NumIn1, NumIn2 : Integer;
  BinaryIn1, BinaryIn2 : String;
  Result : String;

Begin
  Writeln('Combined Denary To Binary Convertor and Binary Adder');
  Writeln;
  Write('Input denary number 1: ');
  Readln(NumIn1);
  Write('Input denary number 2: ');
  Readln(NumIn2);
  BinaryIn1 := ConvertDenaryToBinary(NumIn1);
  BinaryIn2 := ConvertDenaryToBinary(NumIn2);
  Result := AddBinary(BinaryIn1, BinaryIn2);
  Writeln('Result in Binary: ', Result);
  Readln;
End.