def main():
    L=int(input())
    sum,count=0,0
    for i in range(2,L+1):
        if i==2:
            sum=sum+2
        for j in range(2,i):
            if i%j==0:
                break
        else:
            print(i)
            if sum+i>L:
                break 
            sum+=i
            count+=1
    print(count+1)
if __name__=='__main__':
    main()