n = int(input())
for _ in range(n-1):
    a, b = map(int, input().split())

degrees = [0] * (n + 1)
for _ in range(n - 1):
    u, v = map(int, input().split())
    degrees[u] += 1
    degrees[v] += 1

k = sum(1 for i in range(1, n + 1) if degrees[i] % 2 == 1)

additional = (k - 2) // 2
print((n - 1) + additional)