import re
import sys


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

with open(inFile, 'r', encoding='utf-8') as inputFile, open(outFile, 'w', encoding='utf-8') as outputFile:
    for line in inputFile:
        line = line.rstrip()
        words = re.findall(r'\w+', line)

        if len(words) >= 3:
            # Replace the third word with "xxx" string
            third_word = words[2]
            replacement = 'x' * len(third_word)
            words[2] = replacement

            # Print the modified line
            outputFile.write(' '.join(words)+ '\n')
        else:
            # If there are less than 3 words, print the original line
            outputFile.write(line + '\n')