import sys
from collections import defaultdict

def main():
    N = int(sys.stdin.readline())
    red_edges = []
    for _ in range(N-1):
        u, v = map(int, sys.stdin.readline().split())
        red_edges.append((u, v))
    
    black_degrees = defaultdict(int)
    for _ in range(N-1):
        u, v = map(int, sys.stdin.readline().split())
        black_degrees[u] += 1
        black_degrees[v] += 1
    
    count = 0
    for v in black_degrees.values():
        if v % 2 != 0:
            count += 1
    
    if count == 0:
        print(N-1)
    else:
        k = count // 2
        print(N + k - 2)

if __name__ == "__main__":
    main()