    
An integer N (2 ≤ N ≤ 2 * 10^5), representing some quantity or size.
N pairs of integers (A_i, B_i) where 1 ≤ A_i ≤ B_i ≤ 10^9.

### Example Input:

```
3
100 100
10 10000
1 1000000000
```

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