# 全方位木DP
# https://qiita.com/Kiri8128/items/a011c90d25911bdb3ed3#bottom-up-%E9%83%A8%E5%88%86
import sys
input = sys.stdin.readline
from collections import deque

N=int(input())
mod=998244353
X = [[] for i in range(N)]
for i in range(N-1):
    x, y = map(int, input().split())
    X[x-1].append(y-1)
    X[y-1].append(x-1)

P = [-1] * N
Q = deque([0])
R = []
while Q:
    i = deque.popleft(Q)
    R.append(i)
    for a in X[i]:
        if a != P[i]:
            P[a] = i
            X[a].remove(i)
            deque.append(Q, a)

##### Settings
unit = (0,0)
merge = lambda a, b: (max(a)+max(b),a[1]+b[1]) 
adj_bu = lambda a, i: (a[1]+1,a[0])
adj_td = lambda a, i, p: (a[1]+1,a[0])
adj_fin = lambda a, i: (a[1]+1,a[0])
#####

ME = [unit] * N
XX = [0] * N
TD = [unit] * N
for i in R[1:][::-1]:
    XX[i] = adj_bu(ME[i], i)
    p = P[i]
    ME[p] = merge(ME[p], XX[i])
XX[R[0]] = adj_fin(ME[R[0]], R[0])

# print("ME =", ME) # Merge before adj
# print("XX =", XX) # Bottom-up after adj

for i in R:
    ac = TD[i]
    for j in X[i]:
        TD[j] = ac
        ac = merge(ac, XX[j])
    ac = unit
    for j in X[i][::-1]:
        TD[j] = adj_td(merge(TD[j], ac), j, i)
        ac = merge(ac, XX[j])
        XX[j] = adj_fin(merge(ME[j], TD[j]), j)

# print("TD =", TD) # Top-down after adj
# print("XX =", XX) # Final Result

#print(*XX, sep = "\n")

print(min([x[0] for x in XX]))