for tcase in range(int(input())):
    dict={}
    countList=[]
    n = int(input())
    for i in range(n):
        lst = input().split()
        dict[lst[1]] = lst[0]
        countList.append(int(lst[1]))
    countList.sort()
    for i in range(n-1,-1,-1):
        print(dict[str(countList[i])])