n = int(input())
for _ in range(n-1):
    a, b = map(int, input().split())  # Red edges are read but not used
black_edges = [tuple(map(int, input().split())) for _ in range(n-1)]

degree = [0] * (n + 1)
for a, b in black_edges:
    degree[a] += 1
    degree[b] += 1

leaves = sum(1 for i in range(1, n+1) if degree[i] == 1)

print((n-1) + (leaves - 2))