N=int(input())
G=[[] for _ in range(N)]
for _ in range(N-1):
    u,v=map(int,input().split())
    u-=1;v-=1
    G[u].append(v)
    G[v].append(u)
P=set()
def dfs(s,n,c):
    global P
    if s!=n:P.add((s,n) if s<n else (n,s))
    if c==3:return
    for i in G[n]:
        dfs(s,i,c+1)
for i in range(N):
    dfs(i,i,0)
print(len(P))