ProblemDescription withhisclassmatesinhiking:ahostkeepsanumberin  loses,orthehostwilltellalltheplayersthatthenumbernowisbigger

求\(n\)个点的树上对于每个点距离小于\(k\)的点的数量（边权均为\(1\)）。\(n\leq5\times10^5，k\leq10\)。设\(f[u][i]\)表示距离\(u\)点\(i\)距离以内并且