import math


def is_coprime(m: int, n: int) -> bool:
    """Return whether m and n are coprime (review the reading for the definition of coprime).

    Hints:
        - Use the math module's gcd function to calculate the gcd of two numbers.

    >>> is_coprime(3, 7)
    True
    >>> is_coprime(3, 9)
    False
    """
    return math.gcd(m, n) == 1