Input specification: the first line contains n and m (the number of vertices and edges of the graph). The vertices are labeled with numbers 1, 2, ..., n. The first line is followed by m lines, each of these lines describes an edge. The i-th of these lines contains four numbers. The first two numbers specify the end-point vertices, the third number is the weight and the fourth number is either 0 or 1 (1 means the edge belongs to F, 0 means the edge is not in F).
Output specification: the output contains one line with either the cost of a minimum-cost F-containing spanning tree, or -1 if no such spanning tree exists.
Example:
Input:
6 8
1 2 3 1
2 3 7 0
1 4 4 0
3 6 3 0
3 4 2 0
4 5 2 1
5 6 6 1
4 6 1 0
Output:
17