#include <iostream>
#include <cstdio>
#include <algorithm>
using namespace std;
const int N = 500010;
typedef long long ll;
int a[N], backup[N];
int n;
ll merge_sort(int q[], int l, int r){
    if(l == r)  return 0;
    int mid = l + r >> 1;
    ll res = merge_sort(q, l, mid) + merge_sort(q, mid + 1, r);
    int i = l, j = mid + 1, k = 0;
    while(i <= mid && j <= r){
        if(q[i] <= q[j])    backup[k++] = q[i++];
        else{
            res += mid - i + 1;
            backup[k++] = q[j++];
        }
    }
    while(i <= mid)     backup[k++] = q[i++];
    while(j <= r)   backup[k++] = q[j++];
    for(i = l, k = 0; i <= r; i ++, k ++ ){
        q[i] = backup[k];
    }
        return res;
}
int main(){
    while(cin >> n && n != 0){
        for(int i = 0; i < n; i ++ )    scanf("%d", &a[i]);
        cout << merge_sort(a, 0, n-1) << endl;
    }
    return 0;
}