import sys
sys.setrecursionlimit(10000000)
MOD = 10 ** 9 + 7
INF = 10 ** 15

N = int(input())
G = [[] for _ in range(N)]
deg = [0] * N
for _ in range(N - 1):
    a,b = map(int,input().split())
    a -= 1
    b -= 1
    G[a].append(b)
    deg[b] += 1

for i in range(N):
    if deg[i] == 0:
        root = i
        break

dist = [-1] * N
dist[root] = 0
ans = 0
def dfs(i):
    global ans
    cnt = 1
    for e in G[i]:
        if dist[e] >= 0:
            continue
        dist[e] = dist[i] + 1
        cnt += dfs(e)
    ans += cnt*dist[i]
    return cnt

dfs(root)
print(ans)