Solution attempt to the question (google: Hackerrank poisonous biohazard allergic)

Solution.java

import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;

class Result {
    private Result(){}
    /*
     * Complete the 'bioHazard' function below.
     *
     * The function is expected to return a LONG_INTEGER.
     * The function accepts following parameters:
     *  1. INTEGER n
     *  2. INTEGER_ARRAY allergic
     *  3. INTEGER_ARRAY poisonous
     */

    public static long bioHazard(int n, List<Integer> allergic, List<Integer> poisonous) {
        HashMap<Integer, HashSet<Integer>> hashMap = new HashMap<>();
        int index = 0;
        HashSet<Integer> set = null;
        for(int poison: poisonous) {
            if(hashMap.containsKey(poison)){
                hashMap.get(poison).add(allergic.get(index));
            }else {
                set = new HashSet<>();
                set.add(allergic.get(index));
                hashMap.put(poison, set);
            }
            index++;
        }
        int intervals = 0;
        List<Integer> sequence = new ArrayList<>();
        for(int i=1;i<=n;i++) {
            if(hashMap.containsKey(i) && hashMap.get(i).contains(i+1)){
                continue;
            }
            if(hashMap.containsKey(i+1) && hashMap.get(i+1).contains(i)){
                continue;
            }
            sequence.add(i);
        }
        int size = sequence.size();
        long result =(long)Math.pow(2, size) - 1 - size;
        System.out.println(result + n);
        return intervals;
    }

}

public class Solution {
    public static void main(String[] args) {
        List<Integer> a1 = new ArrayList<>();
        a1.add(2);
        a1.add(1);
        a1.add(3);
        List<Integer> a2 = new ArrayList<>();
        a2.add(3);
        a2.add(3);
        a2.add(1);
        long result = Result.bioHazard(3,a1,a2);
        System.out.print(result);
    }
}

Incorrect logic