BOJ - 9872 - Record Keeping

import sys

def solution():
    N = int(sys.stdin.readline())
    groups = [''] * 1001
    for i in range(N):
        arr = list(map(str, sys.stdin.readline().split()))
        arr.sort(reverse=True)
        groups[i] = arr[0] + ' ' + arr[1] + ' ' + arr[2]

    ret = 0
    for i in range(N):
        cnt = 0
        for j in range(N):
            if groups[i] == groups[j]: cnt += 1
        if ret < cnt:
            ret = cnt
    print(ret)
solution()

https://www.acmicpc.net/problem/9872