An integer r (1 ≤ r ≤ 1,000), representing some quantity or size.
An integer c (1 ≤ c ≤ 1,000), representing some quantity or size.
An integer a1 (0 ≤ a1 < r), representing some coordinate.
An integer a2 (0 ≤ a2 < c), representing some coordinate.
An integer b1 (0 ≤ b1 < r), representing some coordinate.
An integer b2 (0 ≤ b2 < c), representing some coordinate.

### Example Input:

```
4 4 0 0 3 3
```

### Function Signature:
Write a function f(r, c, a1, a2, b1, b2) that takes in the input. 
def f(r: int, c: int, a1: int, a2: int, b1: int, b2: int): 
    ''' 
    r: an integer 
    c: an integer
    a1: an integer
    a2: an integer
    b1: an integer
    b2: an integer
    '''