def prime_number(number):
    if number <=3:
        return True
    elif number % 2 == 0 or number % 3 ==0:
        return False
    else:
        i = 5
        while i * i <= number:
            if number % i  == 0 or number % (i+2) == 0:
                return False
            i += 6
    return True
a=int(input())
b=2
c=0
d=0
while a==a:

    if prime_number(b)==True:
        c+=b
        if c>=a:
            break
        print(b)
        d+=1
    b+=1
print(d)