class Solution {
    public List<String> commonChars(String[] words) {
        int[][] arr = new int[words.length][26];
        int n=0;
        
        for(String word:words){
            for(char ch:word.toCharArray()){
                arr[n][ch-'a']++;
            }
            n++;
        }
        
        List<String> list = new ArrayList<>();
        
        for(int i=0; i<26; i++){
            int k=100;
            for(int j=0; j<arr.length; j++){
                k=Math.min(k, arr[j][i]);
            }
            
            while(k-- >0){
                list.add(Character.toString(i+'a'));
            }
        }
        
        return list;
    }
}