import sys
sys.setrecursionlimit(10**8)
input=sys.stdin.readline

def dfs(v):
    nums[v] = 0
    child[v] = 0
    if len(edge[v])==0:
        return
    for u in edge[v]:
        if nums[u] == -1:
            dfs(u)
        nums[v] += nums[u]+child[u]+1
        child[v] += child[u]+1
    return

N = int(input())
edge = [[] for _ in range(N)]
for _ in range(N-1):
    a,b = map(int, input().split())
    edge[a-1].append(b-1)
nums = [-1]*N
child = [-1]*N
for i in range(N):
    if nums[i] == -1:
        dfs(i)
ans = sum(nums)
print(ans)