from math import gcd

N, B = map(int, input().split())

if gcd(N, B) != 1:
    print('NaN')
    exit()


def extgcd(a, b):
    if b == 0: return a, 1, 0
    g, x, y = extgcd(b, a % b)
    return g, y, x - a // b * y


def invmod(a, m):
    g, x, y = extgcd(a, m)
    return x % m


res = invmod(N, B)
print(res)