9
1 3
2 3
3 4
4 5
4 6
4 7
7 8
7 9

3

from collections import deque
n=int(input())
graph=[[] for _ in range(n+1)]
for _ in range(n-1):
    u,v=map(int,input().split())
    graph[u].append(v); graph[v].append(u)
def bfs(start, blocked_u, blocked_v):
    visited={start}; q=deque([start])
    while q:
        node=q.popleft()
        for nxt in graph[node]:
            if nxt not in visited and not (node==blocked_u and nxt==blocked_v) and not (node==blocked_v and nxt==blocked_u):
                visited.add(nxt); q.append(nxt)
    return len(visited)
result=float('inf')
for u in range(1,n+1):
    for v in graph[u]:
        if u<v:
            sz=bfs(u,u,v)
            result=min(result, abs(sz-(n-sz)))
print(result)