백준 30088번: 공포의 면담실 #Python

import sys

N = int(sys.stdin.readline())

time_list = [0] * N

for i in range(N):
    time_list[i] = sum(map(int, sys.stdin.readline().split()[1:]))

sorted_time_list = sorted(time_list)
prefix_sum = [0] * (N + 1)

for j, time in enumerate(sorted_time_list, 1):
    prefix_sum[j] = prefix_sum[j - 1] + time

print(sum(prefix_sum))