write a go solution for Description:
You are given an undirected graph of N nodes and M edges, E_1,E_2,...E_M.

A connected graph is a cactus if each of it's edges belogs to at most one simple cycle. A graph is a desert if each of it's connected components is a cactus.

Find the number of pairs (L,R), (1<=L<=R<=M) such that, if we delete all the edges except for E_L,E_L+1,...E_R, the graph is a desert.

Input Format:
The first line contains two integers N and M (2<=N<=2.5x10^5, 1<=M<=5x10^5). Each of the next M lines contains two integers. The i-th line describes the i-th edge. It contains integers U_i and V_i, the nodes connected by the i-th edge (E_i=(U_i,V_i)). It is guaranteed that 1<=U_i,V_i<=N and U_ineqV_i.

Output Format:
The output contains one integer number – the answer.

Note:
In the second example: Graphs for pairs (1,1), (2,2) and (3,3) are deserts because they don't have any cycles. Graphs for pairs (1,2) and (2,3) have one cycle of length 2 so they are deserts.. Output only the code with no comments, explanation, or additional text.