import java.util.Scanner;

public class Main{
  public static void main(String[] args){
    Scanner scan=new Scanner(System.in);
    int X=scan.nextInt();
	int check=0;
    int Y=X;
    if(X>2){
	for(int i=X;check==0;i++){
      for(int j=2;j<i;j++){
        if(i%j==0){
          break;
        }
        if(j==i-1){
			check=1;
        }
      }
      Y=i;
    }
    }
    System.out.println(Y);
  }
}
/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