def main():
print('введите число листков')
m = int(input())
mainlist = []
kol = 0
coolmen = set()
for i in range(m):
    list = []
    mainlist.append(list)
for i in range(m):
    print('введите число фамилий и сами фамилии')
    n = int(input())
    for j in range(n):
        str = input()
        mainlist[i].append(str)

for i in range(m):
    for j in range(m):
        for k in range(m):
            if mainlist[i][j] in mainlist[k]:
                kol += 1
        if kol == m:
            coolmen.add(mainlist[i][j])
        kol = 0
print(*coolmen)
main()