class Solution {
     public int findMaxForm(String[] strs, int m, int n) {
        int len = strs.length;
        List<int[]> freqs = new LinkedList<int[]>();
        for(int i=0;i<len;i++){
           int[] freq = new int[2];
            String str = strs[i];
            int slen = str.length();
            for(int j=0;j<slen;j++){
                freq[str.charAt(j)-'0']++;

            }
            freqs.add(freq);
        }
       return helper(freqs,0,m,n);

    }


    public int helper(List<int[]> cand, int pos,int m,int n ){
        int len = cand.size();
        int dep = Integer.MIN_VALUE;
        for(int i = pos;i<len;i++){
            int[] temp = cand.get(i);
            m-= temp[0];
            n-= temp[1];
            if(m>=0&&n>=0){
                dep =Math.max(dep,helper(cand,i+1,m,n)+1);
            }
            m+= temp[0];
            n+= temp[1];
        }
       return dep==Integer.MIN_VALUE?0 : dep;
    }

}