import sys

def read():

    ## Read
    output = []
    lines = sys.stdin.readlines()
    for line in lines:
        chars = {}
        for char in line:
            if char in chars:
                chars[char] += 1
            else:
                chars[char] = 1
        if 2 in chars.values():
            output.append(line)

    ## Write
    for line in output:
        print(line)

read()

## How to run it
# echo -e "asdf\nd fm\ndfaa\naaaa\naabb" | python basic_test.py