from collections import deque n,m=map(int,input().split()) edge=[list(map(int,input().split())) for _ in range(m)] E=[[] for _ in range(n+1)] for a,b in edge: E[a].append(b) E[b].append(a) dist=[0]*(n+1) dist[0]=1 D=[10**6]*(n+1) D[1]=0 q=deque([1]) while q: x=q.popleft() for e in E[x]: if D[x]+1