N = int(input())
E = [[] for _ in range(N)]
for _ in range(N-1):
    a,b = map(int, input().split())
    E[a-1].append(b-1)
    E[b-1].append(a-1)

from collections import deque

def f(s):
    q = deque([s])
    dist = [-1]*N
    dist[s] = 1
    while q:
        temp = q.pop()
        for u in E[temp]:
            if dist[u] >= 0:
                continue
            dist[u] = dist[temp]+1
            q.append(u)
    return dist

for i in range(N):
    if len(E[i]) == 1:
        dist1 = f(i)
        break

num = 0
for i in range(N):
    if num < dist1[i]:
        num = dist1[i]
        idx = i

dist2 = f(idx)
num = max(num, max(dist2))
print(N-num)