## https://yukicoder.me/problems/no/415


def calc_gcd(A, B):
    """
    正の整数A, Bの最大公約数を計算する
    """
    a = max(A, B)
    b = min(A, B)
    while a % b > 0:
        c = a % b
        a = b
        b = c
    return b


def main():
    N, D = map(int, input().split())

    gcd = calc_gcd(N, D)
    ans = N // gcd
    print(ans - 1)










if __name__ == "__main__":
    main()