public int checkDataType(String str){
        
        int res = -1;
        char[] c = new char[]{'0','1','2','3','4','5','6','7','8','9'};
        char[] str_array = str.toCharArray();
        char symbol;
        boolean numberOcurrence = false;
        boolean letterOcurrence = false;

        int size = str_array.length;
        for (int i = 0; i < size; i ++) {
            symbol = str_array[i];
            
            if(numberOcurrence && (!isSymbol(c,symbol)) || (letterOcurrence && isSymbol(c,symbol))){
                res = 3;
                break;
            }
            if(isSymbol(c,symbol)){
                numberOcurrence = true;
                if(i == size-1){
                    res = 2;
                    break;
                }
            }
            if(!isSymbol(c,symbol)){
                    letterOcurrence = true;
                    if(i == size-1){
                        res = 1;
                        break;
                    }
            }
        }
        return res;
    }