The General Petrenko interested in the question: What is the greatest integer \textbf{N} multiple of \textbf{M}, can be displayed on the device constructed using the \textbf{K} light-emitting diodes? The number of light-emitting diodes needed to display each of the figures shown. \includegraphics{https://static.e-olymp.com/content/4d/4d37100b8f460a8cd42dfc83df5ab836b073b01d.jpg} \InputFile In one line given two integers \textbf{K} and \textbf{M} through the gap (\textbf{1} ≤ \textbf{K} ≤ \textbf{100}, \textbf{1} ≤ \textbf{M} ≤ \textbf{3000}). \OutputFile Remove only the number \textbf{N} - the answer to the general question. If the solution does not exist, output a \textbf{-1}.