Graph and Cycles#11283

Graph and Cycles

1 second
128 megabytes
Hard

There is an undirected weighted complete graph of vertices where is odd.

Let's define a cycle-array of size as an array of edges [e[1], e[2], ..., e[k]] that has the following properties:

It is obvious that edges in a cycle-array form a cycle.

Let's define (e[1], e[2]) as a function that takes edges e[1] and e[2] as parameters and returns the maximum between the weights of e[1] and e[2].

Let's say that we have a cycle-array = [e[1], e[2], ..., e[k]]. Let's define the price of a cycle-array as the sum of (e[i], e[i+1]) for all from to (consider e[k+1] = e[1]).

Let's define a cycle-split of a graph as a set of non-intersecting cycle-arrays, such that the union of them contains all of the edges of the graph. Let's define the price of a cycle-split as the sum of prices of the arrays that belong to it.

There might be many possible cycle-splits of a graph. Given a graph, your task is to find the cycle-split with the minimum price and print the price of it.

Input

The first line contains one integer (3 \le n \le 999, is odd) - the number of nodes in the graph.

Each of the following n \cdot (n - 1) / 2 lines contain three space-separated integers , and (1 \le u, v \le n, u \neq v, 1 \le w \le 10^9), meaning that there is an edge between the nodes and that has weight .

Output

Print one integer - the minimum possible price of a cycle-split of the graph.

Examples

Example 1

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Example 2

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Note

Let's enumerate each edge in the same way as they appear in the input. I will use e[i] to represent the edge that appears -th in the input.

The only possible cycle-split in the first sample is = {[e[1], e[2], e[3]]}: (e[1], e[2]) + (e[2], e[3]) + (e[3], e[1]) = 1 + 1 + 1 = 3.

The optimal cycle-split in the second sample is = {[e[3], e[8], e[9]], [e[2], e[4], e[7], e[10], e[5], e[1], e[6]]}. The price of [e[3], e[8], e[9]] is equal to , the price of [e[2], e[4], e[7], e[10], e[5], e[1], e[6]] is equal to , thus the price of the split is equal to .