[백준/Python] 13023 ABCDE

n, m = map(int, input().split())
graph = [[] for i in range(n)]
visited = [0 for i in range(n)]
result = [0]

for i in range(m):
    a, b = map(int, input().split())
    graph[a].append(b)
    graph[b].append(a)

def dfs(x, f):
    visited[x] = 1
    
    if f==5:
        result[0] = 1
        return
    for i in graph[x]:
        if visited[i]==0:
            dfs(i, f+1)
            visited[i] = 0

for i in range(n):
    dfs(i, 1)
    visited[i] = 0
    if result[0] == 1:
        break
print(result[0])