def extend_euclid(a, b):
    def inner(a, b, ae, be):
        if b == 0:
            if a == 1:
                return ae
            else:
                return None
        new_be = [0, 0]
        new_be[0] = ae[0] - a // b * be[0]
        new_be[1] = ae[1] - a // b * be[1]
        return inner(b, a%b, be, tuple(new_be))
    return inner(a, b, (1, 0), (0, 1))

N, B = map(int, input().split())
ans = extend_euclid(N, B)
if ans is None:
    print("NaN")
else:
    print(ans[0]%B)