#include<iostream>

using namespace std;

int main()
{
 int n,i,ok,d,gasit;
 cin>>n;
 gasit=0;
 i=n+1;
 while(!gasit)
 {
    ok=1;
    if(i==0 || i==1) ok=0;
    else for(d=2;d<=i/2;d++)
           if(i%d==0) ok=0;
    if(ok) gasit=1;
    else i++;                    
 }   
 cout<<i;
 system("pause");
 return 0;
}