import sys

sys.setrecursionlimit(int(1e7))

N = int(input())
G = [[] for _ in range(N)]
for _ in range(N - 1):
    u, v = map(int, input().split())
    u, v = u - 1, v - 1
    G[u].append(v)
    G[v].append(u)

dist = [0] * N

def dfs1(u, par):
    for v in G[u]:
        if v == par: continue
        dfs1(v, u)
        dist[u] = max(dist[u], dist[v] + 1)

def dfs2(u, d_par, par):
    far = [(0, -1)]
    for v in G[u]:
        if v == par: far.append((d_par + 1, v))
        else: far.append((dist[v] + 1, v))
    far.sort(reverse=True)
    ans, size = 0, len(far)
    for i in range(size):
        c, _ = far[i] 
        ans = max(ans, 1 + (i + 1) * c)
    for v in G[u]:
        if v == par: continue
        ans = max(ans, dfs2(v, far[int(far[0][1] == v)][0], u))
    return ans

dfs1(0, -1)
print(dfs2(0, 0, -1))