INF = 10 ** 10
import sys
sys.setrecursionlimit(100000000)
dy = (-1,0,1,0)
dx = (0,1,0,-1)
from  collections import deque

def main():
    n = int(input())
    ans = []
    cus = []

    for _ in range(n):
        a = list(map(int,input().split()))
        a = a[::-1]
        cus.append(a[:-1])
    
    while True:
        update = False
        for i in range(n):
            if len(cus[i]) > 0:
                p = cus[i].pop()
                ans.append(p)
                update = True

        if not update:
            break
    
    print(*ans)
if __name__ == '__main__':
    main()