t=int(input())
while t:
    n=int(input())
    L=[[0]*2 for i in range(100)]
    T=[0]
    for j in range(0,n):
        L[j]=input().split()
    for i in range(0,n-1):
        for j in range(0,n-i-1):
            if int(L[j][1])>int(L[j+1][1]):
                T=L[j]
                L[j]=L[j+1]
                L[j+1]=T
    for i in range(n-1,-1,-1):
        print(L[i][0])
    t=t-1