{Encyption type 1}
var	fi,fo:file of char;
	g,o:char;
	fid,fod,x:string;
	i,j:byte;
begin
	write('Input file : ');readln(fid);
	write('Output file: ');readln(fod);
	assign(fi,fid);reset(fi);
	assign(fo,fod);rewrite(fo);
        i:=1;
        read(fi,g);
        o:=g;
	while not eof(fi) do
	begin
		read(fi,g);
                {=====}
                while g = o do
		begin
                        inc(i);
			read(fi,g);
		end;
                {=====}
                if i>2 then
                begin
                        x:=chr(0)+chr(i)+o;
                        for j:=1 to 3 do write(fo,x[j]);
                end
                else for j:=1 to i do write(fo,o);
                {=====}
                i:=1;
		o:=g;
        end;
        write(fo,g);
	close(fo);
end.