Given an undirected graph with v vertices and e edges, you are asked to count the number of triangles in the graph.
A triangle in a graph is a set of 3 vertices that any are all connected to each other.
For instance, the graph in the image has 3 triangles:
1-2-5
2-5-4
3-2-4
Input
The first line of the input contains two integers v (1 β€ v β€ 100) and e (1 β€ e β€ ).
The following e lines contain pairs of integers v1, v2 (1 β€ v1, v2 β€ v) which means that the vertex v1 is connected to the vertex v2 and vice versa.
Output
The program should print the number of triangles in the given graph.