def lychrel_test(num):
    n = 1
    while True and (n <= 50):
        r_num = int(str(num)[::-1])
        if (num == r_num) and (n > 1):
            return False
        else:
            num += r_num
        n += 1
    return True

lychrels = set()

for num in range(1, 10000):
    if lychrel_test(num):
        lychrels.add(num)

print(len(lychrels))