def isprime(n):
    for i in range(2, n):
        if n % i == 0:
            return 0
    return 1


n = int(input("请输入一个数据:"))
value_set = set()
for i in range(2, n):
    if isprime(i) == 1:
        value_set.add(i)
print(value_set)