import sys
input = lambda: sys.stdin.readline().rstrip()
mi = lambda: map(int,input().split())
li = lambda: list(mi())
from collections import deque

n = int(input())
g = [[] for i in range(n)]
for i in range(n-1):
    a,b,c = mi()
    a,b = a-1,b-1
    g[a].append((b,c))
    g[b].append((a,c))
    
siz,x = [0]*n,[0]*n
st = deque([0])
now = 0
while st:
    cur = st.pop()
    if siz[cur]:
        for to,weight in g[cur]:
            siz[cur] += siz[to]
    else:
        st.append(cur)
        par_idx = -1
        for i in range(len(g[cur])):
            to,weight = g[cur][i]
            if siz[to]:
                par_idx = i
            else:
                x[to] = x[cur] ^ weight
                st.append(to)
        if par_idx != -1:
            g[cur][-1],g[cur][par_idx] = g[cur][par_idx],g[cur][-1]
            g[cur].pop()
        siz[cur] = 1

sorted_x = sorted(set(x))
for i in range(n):
    ok,ng = 0,len(sorted_x)
    while ng-ok > 1:
        m = (ok+ng) >> 1
        if sorted_x[m] <= x[i]:
            ok = m
        else:
            ng = m
    x[i] = ok

y,cnt,tmp_y,tmp_cnt = [0]*n,[0]*n,[-1]*n,[-1]*n
ans = n*(n-1)

p20 = 1<<20
mask = p20-1
st.append(0)
while st:
    tmp = st.pop()
    cur,step = tmp&mask,tmp//p20
    
    if step == 0:
        ans -= y[x[cur]]
        ans -= siz[cur] * cnt[x[cur]]
        tmp_cnt[cur] = cnt[x[cur]]
        tmp_y[cur] = y[x[cur]]
    
    if step < len(g[cur]):
        cnt[x[cur]] = 1
        y[x[cur]] = n - siz[g[cur][step][0]]
        st.append(cur + p20*(step+1))
        st.append(g[cur][step][0])
    else:
        cnt[x[cur]] = tmp_cnt[cur] + 1
        y[x[cur]] = tmp_y[cur] + siz[cur]

print(ans)