﻿ Fuzhou University OnlineJudge ﻿  Problem 1087 Marbles on a tree

## Problem Description

n boxes are placed on the vertices of a rooted tree, which are numbered from 1 to n, 1 ≤ n ≤ 10000. Each box is either empty or contains a number of marbles; the total number of marbles is n. The task is to move the marbles such that each box contains exactly one marble. This is to be accomplished be a sequence of moves; each move consists of moving one marble to a box at an adjacent vertex. What is the minimum number of moves required to achieve the goal?

## Input

The input contains a number of cases. Each case starts with the number n followed by n lines. Each line contains at least three numbers which are: v the number of a vertex, followed by the number of marbles originally placed at vertex v followed by a number d which is the number of children of v, followed by d numbers giving the identities of the children of v.

The input is terminated by a case where n = 0 and this case should not be processed.

## Output

For each case in the input, output the smallest number of moves of marbles resulting in one marble at each vertex of the tree.

## Sample Input

9 1 2 3 2 3 4 2 1 0 3 0 2 5 6 4 1 3 7 8 9 5 3 0 6 0 0 7 0 0 8 2 0 9 0 0 9 1 0 3 2 3 4 2 0 0 3 0 2 5 6 4 9 3 7 8 9 5 0 0 6 0 0 7 0 0 8 0 0 9 0 0 9 1 0 3 2 3 4 2 9 0 3 0 2 5 6 4 0 3 7 8 9 5 0 0 6 0 0 7 0 0 8 0 0 9 0 0 0

7 14 20

## Source

Waterloo

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