const f:array[1..4,1..2]of -1..1=((1,0),(0,1),(-1,0),(0,-1));
      ch:array[1..4]of char=('R','T','L','B');

type data=record
          x,y:longint;
          end;
     data1=record
          x,y:integer;
          end;

var a:array[1..100]of data;
    t:array[0..110,0..110]of boolean;
    k:array[1..100]of data1;
    closed,open,i,n:longint;

begin
     fillchar(t,sizeof(t),true);
     readln(n);
     for i:=1 to n do
       readln(a[i].x,a[i].y);
     for i:=2 to n do
       t[a[i].x,a[i].y]:=false;
     writeln(a[1].x,' ',a[1].y);
     closed:=1; open:=0;
     k[1].x:=a[1].x;
     k[1].y:=a[1].y;
     while open<closed do
       begin
            inc(open);
            if open<>1 then writeln(',');
            for i:=1 to 4 do
              if not t[k[open].x+f[i,1],k[open].y+f[i,2]] then
                begin
                     write(ch[i]);
                     t[k[open].x+f[i,1],k[open].y+f[i,2]]:=true;
                     inc(closed);
                     k[closed].x:=k[open].x+f[i,1];
                     k[closed].y:=k[open].y+f[i,2];
                end;
       end;
     writeln('.');
end.

> const f:array[1..4,1..2]of -1..1=((1,0),(0,1),(-1,0),(0,-1));
>       ch:array[1..4]of char=('R','T','L','B');
>
> type data=record
>           x,y:longint;
>           end;
>      data1=record
>           x,y:integer;
>           end;
>
> var a:array[1..100]of data;
>     t:array[0..110,0..110]of boolean;
>     k:array[1..100]of data1;
>     closed,open,i,n:longint;
>
> begin
>      fillchar(t,sizeof(t),true);
>      readln(n);
>      for i:=1 to n do
>        readln(a[i].x,a[i].y);
>      for i:=2 to n do
>        t[a[i].x,a[i].y]:=false;
>      writeln(a[1].x,' ',a[1].y);
>      closed:=1; open:=0;
>      k[1].x:=a[1].x;
>      k[1].y:=a[1].y;
>      while open<closed do
>        begin
>             inc(open);
>             if open<>1 then writeln(',');
>             for i:=1 to 4 do
>               if not t[k[open].x+f[i,1],k[open].y+f[i,2]] then
>                 begin
>                      write(ch[i]);
>                      t[k[open].x+f[i,1],k[open].y+f[i,2]]:=true;
>                      inc(closed);
>                      k[closed].x:=k[open].x+f[i,1];
>                      k[closed].y:=k[open].y+f[i,2];
>                 end;
>        end;
>      writeln('.');
> end.

On my mind the input file can contain one of TWO representations.