An integer N (2 ≤ N ≤ 10^5), representing some quantity or size.
N-1 pairs of integers (a_i, b_i) where each integer is between 1 and N.

### Example Input:

```
7
1 2
2 3
2 4
4 6
6 7
7 5
```

### Function Signature:
Write a function f(N, edges) that takes in the input.
def f(N: int, edges: List[Tuple[int, int]]):
    '''
    N: an integer
    edges: a list of tuples of integers
    '''