public static void tran(int a,int b){
        String []table ={"0","1","2","3","4","5","6","7","8","9","A","B","C","D","E","F"};
        ArrayList<String> list = new ArrayList<>();
        int tmp = 0;
        while(a!=0){
            tmp = a%b;
            a = a/b;
            list.add(table[tmp]);
        }
        int len = list.size();
        for(int i = len-1;i>=0;i--){
            System.out.print(list.get(i));
        }
        System.out.println();
    }