G

import java.math.BigInteger;
import java.util.*;
public class EduA {
	public static void main(String []args){
		Scanner sc=new Scanner (System.in);



		int n=sc.nextInt();


	int k=sc.nextInt();




	int[]a= new int[k];

	boolean[]b= new boolean[600000+1];

	int []index= new int[n+1];

	for(int i=0;i<k;i++){
		a[i]=sc.nextInt();
		b[a[i]]=true;
	    index[a[i]]=i;
	}





	for(int i=1;i<n/2 +1;i++){
		if(b[i]&&b[i*2])
		{
			if(index[i]>index[2*i])
			System.out.println((index[i*2]+1)+" "+(index[i]+1));
			else
				System.out.println((index[i]+1)+" "+(index[2*i]+1));
		return;
		}

	}

	System.out.println(0+" "+0);



















	}
}