from collections import defaultdict, deque

N = int(input())

degs = [0] * N
adj = defaultdict(list)
for _ in range(N-1):
    U, V = map(lambda x: int(x)-1, input().split())
    adj[U].append(V)
    adj[V].append(U)

    degs[U] += 1
    degs[V] += 1

leaves = []
for i in range(N):
    if degs[i] == 1:
        leaves.append(i)


def f(w):
    q = deque()
    for v in leaves:
        q.append(deque([v]))

    used = set()
    while q:
        d = q.popleft()

        hd = d[0]
        tl = d[-1]
        # print(f'{d=} {hd=} {tl=}')
        if len(d) == w:
            mi = min(hd, tl)
            ma = max(hd, tl)
            used.add((mi, ma))

        for to in adj[tl]:
            if len(d) > 1 and d[-2] == to: continue

            d2 = d.copy()
            d2.append(to)
            if len(d2) > w:
                d2.popleft()

            q.append(d2)

    return len(used)


ans = f(2) + f(3) + f(4)
print(ans)