#include<stdio.h>
#include<stdlib.h>

int main()
{int n,flag=0;
    freopen("ciur.in","r",stdin);
    freopen("ciur.out","w",stdout);
    scanf("%d",&n);
    for(int i=1;i<=n;i++)
    {
            for(int j=2;j*j<=n;j++)
            {
                    if(i%2==0 && i%j==00)
                    flag=1;
                    }
    if (flag==1)
    printf("%d",i);
            }        
    return 0;
    }