Berland concerned privacy plan blueprint secret however spy neighboring state manage steal Bertown subway schemeThe Bertown Subway n station number 1 n m bidirectional tunnel connect all Bertown Subway consist line to precise type line circular radiala radial line sequence station v1vk k1 station vi vi1 ik connected tunnel station occur line vivj ijA loop line series station v1vk k2 station vi и vi1 connect tunnel in addition station v1 vk connected tunnel no station occur loop line oncenote single station pass number linesaccorde Berland standard can not tunnel station tunnel belong exactly line naturally line tunnel between station way subway tunnel in addition term graph theory subway vertex cactus consider subway graph station vertexe edge tunnel vertex lie simple cycleunfortunately scheme steal spy station tunnel it impossible determine line tunnel correspond but sabotage successfully spy need know minimum maximum number line Bertown subwayhelp