import math


def get_prime_factors(n):
    """Return prime decomposition of an int n
    """
    prime_factors = []
    while n % 2 == 0: 
        prime_factors.append(2) 
        n = n / 2
    for i in range(3, int(math.sqrt(n))+1,2):
        while n % i== 0: 
            prime_factors.append(i)
            n = n / i 
    if n > 2: 
        prime_factors.append(int(n))
    return prime_factors