CHUSO893 PASCAL

var
   a0,a00: string;
   n, m: longint;

procedure tao_xau_dao_nguoc;
var i:longint;
begin
    a00:='';
    for i:=length(a0) downto 1 do
        a00:=a00+a0[i];
end;
procedure giai;
var k, i,lt: longint;
begin
     k:=length(a0);
     lt:=1;
     for i:=1 to n do lt:=lt*2;
     if (m<1) or (m>lt*k) then
     begin
        write(-1);exit;
     end;
     i:=(m-1) div k;
     m:=m-i*k;
     if i mod 2 = 0 then write(a0[m])
     else write(a00[m]);
     //i:=(m-1) mod l+1;
     //if ((m-1) div l) mod 2=1 then i:=l-i+1;
     //timchuso:=ord(a0[i])-ord('0');
end;

begin
     assign(input, 'chuso893.inp');reset(input);
     assign(output, 'chuso893.out');rewrite(output);
     readln(a0);
     readln(n,m);
     tao_xau_dao_nguoc;
     giai;

     close(input);
     close(output);
end.