a,b = map(int,input().split())
c = 1
from math import gcd
g = gcd(a,b)
if c % g != 0:
    print('-1')
else:
    a//=g; b//=g; c//=g
    mas = [[1,0,a],[0,1,b]]
    while True:
        if mas[0][2] == 1:
            x = mas[0][0]
            y = mas[0][1]
            break
        elif mas[1][2] == 1:
            x = mas[1][0]
            y = mas[1][1]
            break
        if mas[0][2] > mas[1][2]:
            pass
        else:
            mas1 = mas[0]
            mas2 = mas[1]
            mas = [mas2,mas1]
        qw = mas[0][2] // mas[1][2]
        mas1 = [mas[0][0]-mas[1][0]*qw,mas[0][1]-mas[1][1]*qw,mas[0][2] - mas[1][2] * qw]
        mas.pop(0)
        mas.append(mas1)
    print((x*c)%b)
    if (((x*c)%b) * a) % b == 1:
        print('Ты тролль')