public class solution {

    public int solution(int[] A) {
        ArrayList <Integer> listToSort = new ArrayList <Integer>();
        int lowestValue = 0;
        for (int i = 0; i<A.length-1; i++){
            if (A[i]>0){
                listToSort.add(A[i]);
            }
        }
        Collections.sort(listToSort);
        for (int i = 0; i<listToSort.size()-1; i++){
            if (listToSort.get(i) > i+1){
                lowestValue = listToSort.get(i);
            }
        }
        return lowestValue;
    }

}