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


def max_depth(s,return_dist = False):
    ans = 0
    idx = 0
    depth = [-1] * n
    depth[s] = 0
    stack = [s]
    while stack:
        p = stack.pop()
        for v in G[p]:
            if  depth[v] >= 0:
                continue
            depth[v] = depth[p] + 1
            if ans < depth[v]:
                ans = depth[v]
                idx = v
            stack.append(v)
    
    if return_dist:
        return ans,idx,depth
    return ans,idx


depth,s = max_depth(0)
max_dep,i,dist = max_depth(s,True)
d = max_dep
ans = 0
while d > 1:
    for e in G[i]:
        if dist[e] == d - 1:
            i = e
            ans += len(G[e]) - 2
            d -= 1
            break
print(ans)