def countTreePaths(tree_nodes, tree_from, tree_to):
    from collections import defaultdict
    MOD = 10**9 + 7
    
    if tree_nodes < 3:
        return 0

    tree = defaultdict(list)
    for u, v in zip(tree_from, tree_to):
        tree[u].append(v)
        tree[v].append(u)

    size = [0] * tree_nodes
    visited = [False] * tree_nodes

    def dfs(node):
        visited[node] = True
        total_size = 1
        for neighbor in tree[node]:
            if not visited[neighbor]:
                total_size += dfs(neighbor)
        size[node] = total_size
        return total_size

    dfs(0)

    total_triplets = tree_nodes * (tree_nodes - 1) * (tree_nodes - 2) // 6
    
    for node in range(tree_nodes):
        if size[node] < 2:
            continue
        total_invalid = size[node] * (size[node] - 1) // 2 * (tree_nodes - size[node])
        total_triplets -= total_invalid
        total_triplets %= MOD

    return total_triplets   



 
countTreepath // gameskraft💯👍