from collections import deque

n, connections = 6, [[3,6],[4,3],[3,2],[1,3],[1,2],[2,4],[5,2]]

graph = [[] for _ in range(n + 1)]
for a, b in connections:
    graph[a].append(b)
    graph[b].append(a)

dist = [-1] * (n + 1)
dist[1] = 0
queue = deque([1])

while queue:
    node = queue.popleft()
    for neighbor in graph[node]:
        if dist[neighbor] == -1:
            dist[neighbor] = dist[node] + 1
            queue.append(neighbor)

max_dist = max(dist[1:])
print(dist[1:].count(max_dist))