Index: lib/typical/unionfind.cpp
==================================================================
--- lib/typical/unionfind.cpp
+++ lib/typical/unionfind.cpp
@@ -13,10 +13,12 @@
 
 	UnionFind(int N): uf(N), sz(N,1), nc(N)
 		{ for(int i=0; i<N; ++i) uf[i] = i; }
 	int size()
 		{ return nc; }
+	int size(int a)
+		{ return sz[Find(a)]; }
 	int Find(int a)
 		{ return uf[a]==a ? a : uf[a]=Find(uf[a]); }
 	bool Union(int a, int b)
 		{
 			a = Find(a);