import java.util.*;

class Main{
    public static void main(String args[]) {
        Scanner sc = new Scanner(System.in);
        int x = sc.nextInt();
        if(x==2){
            System.out.println(x);
            return;
        }
        while(true){
            boolean isMod = true;
            for(int i=2;i<Math.sqrt(x);i++){
                if(x%i==0){
                    isMod = false;
                    break;
                }
                else{
                    isMod = true;
                }
            }
            if(isMod){
                System.out.println(x);
                return;
            }
            x++;
        }
        
    }
}

/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz