#!/usr/bin/env python3
from functools import reduce


def swap(l, i):
    l[i[0] - 1], l[i[1] - 1] = l[i[1] - 1], l[i[0] - 1]
    return l


def shufle(bars, l):
    return [bars[x] for x in l]

N = int(input())
K = int(input())
initial = list(range(N))
bar = [()] * K
for i in range(K):
    bar[i] = tuple(map(int, input().split()))

bars = list(reduce(swap, bar, list(initial)))
l = shufle(bars, list(initial))
count = 1
while l != initial:
    l = shufle(bars, l)
    count += 1
print(count)