import collections


INF = 10 ** 8


def breadth_first_search(adj_list, start_v):
    n = len(adj_list)
    visited = [False] * n
    pred = [None] * n
    dist = [INF] * n
    q = collections.deque()
    q.append(start_v)
    visited[start_v] = True
    dist[start_v] = 0
    while q:
        u = q.popleft()
        for v in adj_list[u]:
            if not visited[v]:
                visited[v] = True
                pred[v] = u
                dist[v] = dist[u] + 1
                q.append(v)
    return pred, dist


def solve(adj_list):
    n = len(adj_list)
    s = 0
    _, dist_a = breadth_first_search(adj_list, s)
    u = max(range(n), key=lambda x: dist_a[x])
    pred, dist_b = breadth_first_search(adj_list, u)
    v = max(range(n), key=lambda x: dist_b[x])
    path = [v]
    while path[-1] != u:
        path.append(pred[path[-1]])
    res = 0
    for w in path:
        if w != v and w != u:
            res += sum(x != v and x != u for x in adj_list[w])
    return res


def main():
    n = int(input())
    adj_list = [set() for _ in range(n)]
    for _ in range(n - 1):
        a, b = (int(z) - 1 for z in input().split())
        adj_list[a].add(b)
        adj_list[b].add(a)
    print(solve(adj_list))


if __name__ == "__main__":
    main()