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,par = [0]*n,[0]*n,[-1]*n
st1 = deque([0])
while st1:
    cur = st1.pop()
    if siz[cur]:
        g[cur].sort(key = lambda val: -siz[val[0]])
        for to,weight in g[cur]:
            siz[cur] += siz[to]
    else:
        st1.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
                par[to] = cur
                st1.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_sum,cnt_sum = [0]*len(sorted_x),[0]*len(sorted_x)
y,cnt = [-1]*n, [-1]*n
ans = n*(n-1)

st1.append(0)
st2 = deque([])
p30,p31 = 1<<30,1<<31
mask = p30-1
while st1:
    tmp = st1.pop()
    cur1,flag,step = tmp&mask,tmp&p30,tmp&p31

    if step == 0:
        st1.append(cur1 | flag | p31)
        for i in range(len(g[cur1])):
            st1.append(g[cur1][i][0] | (int(i != 0) * p30))
    else:
        st2.append(cur1)
        #dfs1-begin
        while st2:
            cur2 = st2.pop()
            y_sum[x[cur2]] += y[cur2];
            cnt_sum[x[cur2]] += cnt[cur2];
            for to,weight in g[cur2]:
                st2.append(to)
        #dfs1-end
        
        if y[cur1] == -1:
            y[cur1] = siz[cur1] - y_sum[x[cur1]]
            cnt[cur1] = 1 - cnt_sum[x[cur1]]
        ans -= y_sum[x[cur1]]#case-1
        y_sum[x[cur1]] += y[cur1]
        cnt_sum[x[cur1]] += cnt[cur1]

        if cur1 == 0:
            for j in range(len(sorted_x)):
                if j != x[cur1]:
                    ans -= y_sum[j] * cnt_sum[j]#case-3
        else:
            ans -= cnt_sum[x[par[cur1]]] * (n - siz[cur1])#case-2
            ans -= y_sum[x[par[cur1]]] * cnt_sum[x[par[cur1]]]#case-3
            ans += siz[cur1]#case-3
        
        if flag:
            st2.append(cur1)
            #dfs1-begin
            while st2:
                cur2 = st2.pop()
                y_sum[x[cur2]] -= y[cur2];
                cnt_sum[x[cur2]] -= cnt[cur2];
                for to,weight in g[cur2]:
                    st2.append(to)
            #dfs1-end

print(ans)