program test_f_name(input,output);
type string31=packed array[1..31]of char;
var  filename:string31;

function fnok(s:string31;write_to:boolean):boolean;
var i,dot,sub:integer;fail,ftype:packed array[0..4]of boolean;done:boolean;

function my_file(s:string31):boolean;
const
  userad=2359296;{str6}
type
  str6=packed array[0..6]of char;
     cheat=record
         dummyi:integer;
         case boolean of
            true:(addr:integer);
            false:(ptr:^str6)
         end;
  var peeker:cheat;me,owner:str6;i:integer;
  begin
     peeker.addr:=userad;
     me:=peeker.ptr^;
     owner[0]:=chr(6);
     for i:=1 to 6 do owner[i]:=s[i];
{     writeln('OWNER=',owner,'    ME=',me,'     result=',me=owner);            }
     my_file:=owner=me;
  end;


function alphabetical(ch:char):boolean;
begin
alphabetical:=((ord('A')<=ord(ch))and(ord(ch)<=ord('Z')));
end;

function alphanumeric(ch:char):boolean;
begin
alphanumeric:=((ord('0')<=ord(ch))and(ord(ch)<=ord('9')))or alphabetical(ch);
end;

begin
for i:=0 to 4 do begin ftype[i]:=false;fail[i]:=false; end;
dot:=0;sub:=0;
for i:=1 to 31 do if s[i]='.' then dot:=i;
for i:=31 downto 1 do if s[i]='_' then sub:=i;
fail[1]:=((dot<>0)and(dot<>7))or((sub<>0)and(dot+1>=sub));
if dot<>0 then if not fail[1] then for i:=1 to 6 do fail[1]:=fail[1] or not
                                        alphanumeric(s[i]);
ftype[1]:=not fail[1] and (dot<>0);
fail[0]:=fail[1];
if not fail[0] then begin
   i:=dot+1;fail[2]:=not alphabetical(s[i]);
   repeat
      i:=i+1;done:=(s[i]=' ')or(s[i]='_');
      fail[2]:=not (alphanumeric(s[i])or(s[i]='#')or done)or fail[2];
   until done or fail[2] or (i=dot+12);
   fail[2]:=fail[2] or not done;
end;
fail[0]:=fail[1] or fail[2];
if not fail[0] then begin
   ftype[3]:=sub<>0;
   if ftype[3] then begin
       i:=sub+1;
       fail[3]:=not alphabetical(s[i]);
{       repeat                                                                 }
{          done:=s[i]=' ';                                                     }
{          fail[3]:=NOT DONE AND(fail[3] or not (alphanumeric(s[i])));         }
{          i:=i+1;                                                             }
{       until done or fail[3] or (i=sub+12);                                   }
       while not (fail[3] or done or (i=sub+12))do begin
           i:=i+1;done:=s[i]=' ';
           fail[3]:=not done and not alphanumeric(s[i]);
       end;
       fail[3]:=fail[3] or not done;
    end;

end;
fail[0]:=fail[1] or fail[2] or fail[3];
if fail[0] then begin
    write('Invalid ');
    if fail[1] then write('username ') else
        if fail[2] then write('filename ') else
            if fail[3] then write('member name ');
    writeln(s);
end else begin
  if write_to then begin
      if ftype[1] and not my_file(s) then  begin
            writeln('Invalid access - you can''t write to another user''s file');
            fail[4]:=true;
       end else begin
           if ftype[3] then begin
    writeln('Invalid access - you can''t write to a partitioned file member ');
         fail[4]:=true;
            end;
       end;
    end;
end;
fnok:=not(fail[1] or fail[2] or fail[3] or fail[4]);
end;

procedure readstr(var s:string31);
var i:integer;
begin
for i:=1 to 31 do s[i]:=' ';
i:=1;
while input^=' ' do get(input);
while (i<=31) and not eoln do begin read(s[i]);i:=succ(i);end;
if i=1 then readstr(s);
end;

begin
repeat
readstr(filename);
if fnok(filename,false) then writeln(filename,'an be read');
if fnok(filename,true) then writeln(filename,'can be written to');
until false;
end.