The first line contains two integers 𝑛, 𝑚 — the number of vertices and the number of edges in the graph.
The 𝑖-th of the next 𝑚 lines contains two integers 𝑎𝑖, 𝑏𝑖 representing an edge connecting 𝑎𝑖 and 𝑏𝑖
Example :
3 3
1 2
1 3
2 3
Means there are edges from 1 to 2, 1 to 3 and 2 to 3.