import sys
from itertools import groupby


def input(): return sys.stdin.readline().rstrip('\n')


def main():
    n = int(input())
    s = sorted(len(input()) - 2 for _ in range(n))
    z = [(len(list(v)), k) for k, v in groupby(s)]
    print(max(z)[1])


if __name__ == '__main__':
    main()