import java.io.*;

import java.util.*;

import java.text.*;

import java.math.*;

import java.util.regex.*;

public class Solution {

static int getMoneySpent(int[] keyboards, int[] drives, int s, int n, int m){

// Complete this function

int amt = 0;

for(int i=0;i<n;i++){

for(int j=0;j<m;j++){

if((keyboards[i]+drives[j])>amt&&(keyboards[i]+drives[j])<=s){

amt = keyboards[i]+drives[j];

}

}

}

if(amt>0) {

return amt;

}

else return -1;

}

public static void main(String[] args) {

Scanner in = new Scanner(System.in);

int s = in.nextInt();

int n = in.nextInt();

int m = in.nextInt();

int[] keyboards = new int[n];

for(int keyboards_i=0; keyboards_i < n; keyboards_i++){

keyboards[keyboards_i] = in.nextInt();

}

int[] drives = new int[m];

for(int drives_i=0; drives_i < m; drives_i++){

drives[drives_i] = in.nextInt();

}

// The maximum amount of money she can spend on a keyboard and USB drive, or -1 if she can't purchase both items

int moneySpent = getMoneySpent(keyboards, drives, s, n, m);

System.out.println(moneySpent);

}

}