Viết chương trình tạo ra một file F3 chứa các số nguyên bằng cách nối hai file số nguyên F1 và F2

Program GHEP_FILE;
Uses Crt;
Var f1,f2,f3: file of Integer;
fn1,fn2,fd:String;
i: Integer;
Begin
      Clrscr;
      Write('Nhap file nguon 1: '); Readln(fn1);
      Write('Nhap file nguon 2: '); Readln(fn2);
      Write('Nhap file dich 3: '); Readln(Fd);
      Assign(f1,fn1);
      Reset(f1);
      Assign(f2,fn2);
      Reset(f2);
      Assign(f3,Fd);
      Rewrite(f3);
      While not eof(f1) do
      Begin
            Read(f1,i);
            Write(f3,i);
      End;
      While not eof(f2) do
      Begin
            Read(f2,i);
            Write(f3,i);
      End;
      Writeln('Noi dung cua file nguon 1:');
      Writeln('-------------------------------');
      seek(f1,0);
      While not eof(f1) do
      Begin
            Read(f1,i);
            Write(i:4);
      End;
      Close(f1);
      Readln;
      Writeln('Noi dung cua file nguon 2:');
      Writeln('--------------------------------');
      seek(f2,0);
      While not eof(f2) do
      Begin
            Read(f2,i);
            Write(i:4);
      End;
      Close(f2);
      Readln;
      Writeln('Noi dung cua file ghep:');
      Writeln('---------------------------');
      seek(f3,0);
      While not eof(f3) do
      Begin
            Read(f3,i);
            Write(i:4);
      End;
Readln;
End.