某村很多片麦田，为了灌溉这些麦田，村里在第一个麦田挖了一口水井，所有的麦田都从这口井来引水灌溉。还要建立一些水渠，以连接水井和麦田，可以利用部分麦田作为“中转站”，利用水渠连接不同的麦田，只要一片麦田能被灌溉，则与其连接的麦田也能被灌溉。已知哪些麦田之间可以建设水渠和建设每个水渠所需要的费用（注意不是所有麦田之间都可以建立水渠）。编程求解：灌溉所有麦田最少需要多少费用来修建水渠，以及修建水渠的连接说明。

[基本要求]

输入格式 输入的第一行包含两个正整数n, m，分别表示麦田的片数和可以建立的水渠的数量。麦田使用1, 2, 3, ……依次标号。 接下来m行，每行包含三个整数ai, bi, ci，表示第ai片麦田与第bi片麦田之间可以建立一条水渠，所需要的费用为ci。

输出格式。 输出一个整数，表示灌溉所有麦田所需要的最小费用。及水渠连接说明。

输入样例

4 4

1 2 1

2 3 4

2 4 2

3 4 3

输出样例 6 说明：建立以下三条水渠：麦田1与麦田2、麦田2与麦田4、麦田4与麦田3

-Many pieces village wheat fields, in order to irrigate the wheat field, the first village in a wheat field dug a well, all the wheat fields are irrigated by water coming　the wells. But also to establish some canals to connect the wells and wheat fields, wheat fields can be used as part of a " transit station" , the use of drains connected to different crop, irrigation can be as long as a field of wheat, the wheat fields can also be connected thereto irrigation. What can build canals between wheat fields and construction costs required for each canal is known (can be established between the note that not all wheat field drains). Programming Solver: How much irrigated wheat fields all need to minimize the cost to build the canal, and the construction of canals connecting instructions. [Basic requirements] The first line of input formats of input contains two positive integers n, m, respectively, the number represents the number of pieces of wheat fields and can build the canal.