Procedure wr( ch: char; c: integer );
var i: integer;
begin for i := 1 to c do write(ch); end;
procedure square( n: integer );
var i: integer;
begin wr( '*', n ); writeln;
for i := 2 to n-1 do begin write( '*' ); wr( ' ' ); writeln( '*' ); end;
wr( '*', n ); writeln; end;