def merge(l: list, start: int, end: int, end2: int) -> None:

    n1 = end - start + 1
    n2 = end2 - end

    left = [0] * (n1)
    right = [0] * (n2)

    for i in range(n1):
        left[i] = l[start + i]

    for i in range(n2):
        right[i] = l[end + 1 + i]

    i = 0
    j = 0
    k = start

    while i < n1 and j < n2:
        if left[i] <= right[j]:
            l[k] = left[i]
            i += 1
        else:
            l[k] = right[j]
            j += 1
        k += 1

    while i < n1:
        l[k] = left[i]
        j += 1
        k += 1

    while j < n2:
        l[k] = right[j]
        j += 1
        k += 1

def merge_sort(l: list, left: int, right: int) -> None:
    if left < right:

        m = left + (right - 1) // 2

        merge_sort(l, left, m)
        merge_sort(l, m + 1, right)
        merge(l, left, m, right)


def main():
    lines: list[str] = []
    test_cases = int(input())
    while (test_cases != 0):
        n = int(input())

        while (n != 0):

            lines.append(input())

            n -= 1

        merge_sort(lines, 0, len(lines) - 1)
        for line in lines:
            print(line)

        lines = []

        test_cases -= 1

if __name__ == "__main__":
    main()