program three;
var
n,i,j,m,f:integer;
s:char;
begin
writeln('');
readln(n);
j:=i;
writeln('');
readln(s);
writeln;
write(s:n);
m:=j;
m:=m+1;
j:=j-1;
repeat
write(s:j);
write(s:m);
writeln;
j:=j-1;
m:=m+1;
until j=0;
readln;
end.


