import java.util.*;
public class Main{
public static int gcd(int a,int b)
{
int max=Math.max(a,b);
int min=Math.min(a,b);
if(max%min==0) return min;
else return gcd(min,max%min);
}
public static int lcm(int a,int b)
{
return a*b/gcd(a,b);
}
public static int LCM1(int a,int b)
{
int lcm=b;
while(true) {
boolean flag=false;
for(int i=a;i<=b;i++)
{
if(lcm%i!=0)
{
flag=true;
break;
}
}
if(flag) lcm++;
else
{
break;
}
}
return lcm;
}
public static void main(String args[]){
Scanner in=new Scanner(System.in);
int n=in.nextInt();
int m=n;
while(true){
if(LCM1(1,m)==LCM1(n+1,m))
{
System.out.println(m);
break;
}
else m++;
}
}
}