import re
import sys

inFile = sys.argv[1]
outFile = sys.argv[2]

def substitute_digits(match):
    return ''.join(chr(ord('a') + int(digit)) for digit in match.group())

def analyze_line(line):
    result = re.sub(r'\d{4}', substitute_digits, line)
    return result

if __name__ == "__main__":
    try:
        with open(inFile, 'r', encoding='utf-8') as inputFile, open(outFile, 'w', encoding='utf-8') as outputFile:
            for line in inputFile:
                line = line.rstrip()

                modified_line = analyze_line(line)
                outputFile.write(modified_line +'\n')
                print(modified_line)


    except EOFError:
        pass