public static int makeAnagram(String a, String b) {
        int[] arrs = new int['z' + 1];
        
        // Traverse a, b
        for (char c : a.toCharArray()) {
            arrs[c]++;
        }
        for (char c : b.toCharArray()) {
            arrs[c]--;
        }
        
        // Extract the additional values
        return Arrays.stream(arrs) //
                        .reduce(0, (v1, v2) -> v1 + Math.abs(v2));
    }