노트

v = int(input()) e = int(input()) graph = [[] for _ in range(v+1)] for _ in range(e): a, b = map(int, input().split()) graph[a].append(b) graph[b].append(a) def dfs(x): global count visited[x] = True count += 1 for node in graph[x]: if visited[node]: continue dfs(node) count = 0 visited = [False for _ in range(v+1)] dfs(1) print(count-1)