python
def main():
v = 0
e = 0
N = int(input())
for i in range(N):
v += (N - i) * (i + 1)
for i in range(N - 1):
v1, v2 = sorted(map(int, input().split()))
v1 -= 1
v2 -= 1
e += (N - v2) * (v1 + 1)
debug(": e, v", e, v)
print(v - e)