import re
import sys


def analyze_line(line):
    word_pattern = r'\w+'
    pattern = re.compile(r'(\w+ \w+ )(\w+)(.*)')
    words = re.findall(word_pattern, line)
    if len(words) >= 3:
        modified_line = re.sub(pattern, r'\1' + 'x' * len(words[2]) + r'\3', line, count=1)
        return modified_line
    else:
        return line

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(analyze_line(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)