# UnionFind 参考は以下のサイト # https://note.nkmk.me/python-union-find/ from collections import defaultdict class UnionFind(): def __init__(self, n): self.n = n self.parents = [-1] * n def find(self, x): if self.parents[x] < 0: return x else: self.parents[x] = self.find(self.parents[x]) return self.parents[x] def union(self, x, y): x = self.find(x) y = self.find(y) if x == y: return if self.parents[x] > self.parents[y]: x, y = y, x self.parents[x] += self.parents[y] self.parents[y] = x def size(self, x): return -self.parents[self.find(x)] def same(self, x, y): return self.find(x) == self.find(y) def members(self, x): root = self.find(x) return [i for i in range(self.n) if self.find(i) == root] def roots(self): return [i for i, x in enumerate(self.parents) if x < 0] def group_count(self): return len(self.roots()) def all_group_members(self): group_members = defaultdict(list) for member in range(self.n): group_members[self.find(member)].append(member) return group_members def __str__(self): return '\n'.join(f'{r}: {m}' for r, m in self.all_group_members().items()) N = int(input()) ABC = [list(map(int, input().split())) for _ in range(N-1)] mod = 10**9+7 ans = 0 i = 1 while i<2**32: uf = UnionFind(N) for a,b,c in ABC: if c&i>0: uf.union(a-1,b-1) GM = uf.all_group_members() for k,L in GM.items(): l = len(L) ans = (ans+(l-1)*l//2*i)%mod i*=2 print(ans)