N = int(input())
UV = [list(map(int, input().split())) for _ in range(N - 1)]
D = [0] * N
E = [[] for _ in range(N)]
for u, v in UV:
    u -= 1
    v -= 1
    E[u].append(v)
    E[v].append(u)

def bfs(a):
    q = [a]
    cnt = 0
    nv = [True] * N
    nv[a] = False
    while q:
        q2 = []
        lastq = q[:]
        while q:
            x = q.pop(-1)
            for y in E[x]:
                if nv[y]:
                    nv[y] = False
                    q2.append(y)
        q, q2 = q2, q
        cnt += 1
    return (cnt, lastq)

cnt, lastq = bfs(0)
cnt, lastq = bfs(lastq[0])
print(N - cnt)