import sys input = sys.stdin.readline mod=10**9+7 n,m=map(int,input().split()) class Union_find(): def __init__(self, N): # N要素のUnion_find. A.Union_find(N)で作る. self.Group = [i for i in range(N)] self.Nodes = [1]*(N) def find(self,x): # find(a)=find(b)のとき同じグループ while self.Group[x] != x: x = self.Group[x] return x def Union(self,x,y): if self.find(x) != self.find(y): if self.Nodes[self.find(x)] < self.Nodes[self.find(y)]: self.Nodes[self.find(y)] += self.Nodes[self.find(x)] self.Nodes[self.find(x)] = 0 self.Group[self.find(x)] = self.find(y) else: self.Nodes[self.find(x)] += self.Nodes[self.find(y)] self.Nodes[self.find(y)] = 0 self.Group[self.find(y)] = self.find(x) uf1=Union_find(n) uf2=Union_find(n) TO=[i for i in range(n)] TO2=[i for i in range(n)] Parent=[-1]*(2*n+1) for i in range(m): x,y=map(int,input().split()) x-=1 y-=1 k=uf1.find(x) l=uf1.find(y) to_k=TO[k] to_l=TO[l] if k==l: continue if uf1.Nodes[k]