FCSC 2022 - Some challenge about python hash that I don't remember its name

pyhash.py

p1 = 11400714785074694791
p2 = 14029467366897019727
p5 = 2870177450012600261
mask = (1 << 64) - 1


def rol(x, l):
    return ((x << l) | (x >> (64 - l))) & mask


def tuplehash(tup):
    acc = p5
    for x in tup:
        lane = hash(x)
        acc += lane * p2
        acc &= mask
        acc = rol(acc, 31)
        acc *= p1
        acc &= mask
    acc += len(tup) ^ (p5 ^ 3527539)
    acc &= mask
    if acc & (1 << 63):
        acc -= 1 << 64
    return acc


from random import randint

def find_preimage_tuple(target):
    while True:
        M = 2**64
        a = randint(1, 1 << 60)
        t = rol(((target - (2 ^ p5 ^ 3527539)) & mask) * pow(p1, -1, M) % M, 33)
        s = (rol((p5 + a * p2) & mask, 31) * p1) & mask
        b = (t - s) * pow(p2, -1, M) % M
        if hash(a) == a and hash(b) == b and hash((a,b)) == target:
            return (a,b)

find_preimage_tuple(hash('flag'))
# FCSC{658232b18ebebc53c42dd373c6e9bc788f1fd5693cf8a45bcafbff46dae42e24}