from collections import Counter

def adv_6():
    with open('input_adv_6.txt') as f:
        data = [i.strip() for i in f]
        lenght_x = len(data[0])
        rows = [[i[c] for i in data] for c in range(lenght_x)]
        return ''.join([Counter(i).most_common(1)[0][0] for i in rows])

if __name__ == '__main__':
    print(adv_6())