SODAO1 PASCAL

var x,y,a: longint;
begin
    assign(input,'sodao.inp');reset(input);
    assign(output,'sodao.out');rewrite(output);
    read(x);
    y:=0;
    while x>0 do
    begin
           a:=x mod 10;     //lay chu so cuoi x
           x:=x div 10;     //xoa chu so cuoi x
        y:=y*10+a;     //noi them chu so a vao sau so y
    end;
    writeln(y mod 19);
end.