#include<cstdio>
#include<cstring>
using namespace std;
const int maxn=500010;
int a[maxn],b[maxn];
long long cnt;

void Merge(int low,int mid,int high)//合并函数
{
    int i=low,j=mid+1,k=low;
    while(i<=mid&&j<=high) {//按从小到大存放到辅助数组B[]中
        if(a[i]<=a[j])
            b[k++]=a[i++];
        else
        {
        	b[k++]=a[j++];
        	cnt+=(long long)(mid-i+1);
		}   
    }
    while(i<=mid) b[k++]=a[i++];//将数组中剩下的元素放置B中
    while(j<=high) b[k++]=a[j++];
    for(k=low;k<=high;k++)
        a[k]=b[k];
}

void MergeSort(int low,int high)//合并排序
{
    if(low<high)
    {
        int mid=(low+high)>>1;//取中点
        MergeSort(low,mid);//对A[low:mid]中的元素合并排序
        MergeSort(mid+1,high);//对A[mid+1:high]中的元素合并排序
        Merge(low,mid,high);//合并
    }
}

int main()
{
	int n;
	while(scanf("%d",&n)&&n)
	{
		cnt=0;
		for(int i=0;i<n;i++)
			scanf("%d",&a[i]);
		MergeSort(0,n-1);
		printf("%lld\n",cnt);//%I64d
	}
	return 0;	
}