#include <iostream>

 const int MAX = ;

 int a[MAX];

 int swap[MAX];        //临时数组

 int n;                //数组a的长度

 __int64 result;            //数组a中的逆序数

 //归并两个已经有序的段：a[low]—a[mid]和a[mid+1]—a[high]，使得a[low]—a[high]有序。

 void merge(int low, int mid, int high)

 {

     int i = low;

     int j = mid + ;

     int m = ;

     while(i <= mid && j <= high)

     {

         if(a[i] <= a[j])

         {

             swap[m++] = a[i];

             i++;

         }

         else

         {

             swap[m++] = a[j];

             j++;

             result += mid - i + ;

         }

     }

     while(i <= mid)

     {

         swap[m++] = a[i];

         i++;

     }

     while(j <= mid)

     {

         swap[m++] = a[j];

         j++;

     }

     for(i = ; i < m; i++)

         a[low + i] = swap[i];

 }

 //归并排序：对a[low]—a[high]进行归并排序。

 void mergeSort(int low, int high)

 {

     int mid;

     if(low < high)

     {

         mid = (low + high) /;

         mergeSort(low, mid);

         mergeSort(mid + , high);

         merge(low, mid, high);

     }

 }

 int main()

 {

     int i;

     while(true)

     {

         scanf("%d",&n);

         if(n == ) break;

         result = ;

         for(i = ; i < n; i++)

             scanf("%d",a+i);

         mergeSort(, n-);

         printf("%I64d\n",result);

     }

     return ;

 }