#include<iostream>

#include<cstdio>

#include<cstring>

#include<algorithm>

#define maxn 500005

using namespace std;

int n,f[maxn];

long long tmp[maxn],a[maxn],sum;

void add(int k)

{

    while(k)

    {

        f[k]++;

        k-=k&-k;

    }

}

int query(int k)

{

    int ret=;

    while(k<=n)

    {

        ret+=f[k];

        k+=k&-k;

    }

    return ret;

}

int main()

{

    while()

    {

        sum=;

        memset(f,,sizeof f);

        scanf("%d",&n);

        if(!n)return ;

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

            scanf("%lld",&a[i]),tmp[i]=a[i];

        sort(tmp+,tmp+n+);

        unique(tmp+,tmp+n+);

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

            a[i]=lower_bound(tmp+,tmp+n+,a[i])-tmp;

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

        {

            sum+=query(a[i]);

            add(a[i]);

        }

        printf("%lld\n",sum);

    }

}