import re
import sys
def replace_digits_with_letters(input_string):
    digit_to_letter = {'0': 'a', '1': 'b', '2': 'c', '3': 'd', '4': 'e', '5': 'f', '6': 'g', '7': 'h', '8': 'i', '9': 'j'}

    def replace(match):
        number = match.group()
        replaced_number = ''.join(digit_to_letter[digit] for digit in number)
        return replaced_number

    pattern = re.compile(r'\b\d{4}\b|\d{4}')
    result = pattern.sub(replace, input_string)

    return result


def write_answer(row, ouput_file):
    with open(ouput_file, "a", encoding="utf-8") as file:
        file.write(row)


def main_function(input_file, output_file):
    with open(output_file, "w", encoding="utf-8") as output_file1:
        with open(input_file, "r", encoding="utf-8") as file:
            for row in file:
                write_answer(replace_digits_with_letters(row), output_file)

# output_file ='simple.out'
# input_file = 'simple.in'
input_file = sys.argv[1]
output_file = sys.argv[2]
main_function(input_file, output_file)