'''
归并排序求逆序对个数即可
'''


import bisect

def merge_sort(arr):
    if len(arr) == 1:
        return arr.copy(), 0

    mid = (len(arr)-1) // 2
    arr1, cnt1 = merge_sort(arr[:mid+1])
    arr2, cnt2 = merge_sort(arr[mid+1:])

    cnt = cnt1 + cnt2
    for val in arr1:
        idx = bisect.bisect_left(arr2, val)
        if idx - 1 >= 0 and idx - 1 < len(arr2):
            cnt += idx

    arr.sort()
    ret = arr.copy()
    ret.sort()
    return ret, cnt


while True:
    n = int(input())
    if n == 0:
        break

    arr = [0] * n
    for i in range(n):
        arr[i] = int(input())

    print(merge_sort(arr)[1])