#include<iostream>
#include<algorithm>
using namespace std;
const int N= 5e5+3e3;
using ll=long long ;
ll n,m,i,j,k,a[N],b[N],cnt=0;
void merge(ll a[],ll left,ll r){
if(r-left<1){
return;
}
ll mid=(left+r)>>1;
merge(a,left,mid);
merge(a,mid+1,r);
ll i=left,j=mid+1;
for(k=left;k<=r;++k){
if(j>r||i<=mid&&a[i]<=a[j]){
b[k]=a[i++];
}else{
cnt+=mid-i+1;
b[k]=a[j++];
}
}
for(k=left;k<=r;++k){
a[k]=b[k];
}
}
int main(){
ios::sync_with_stdio(false);
cin.tie(0);
while(cin>>n&&n){ //while have input and not zero
for(i=1;i<=n;++i){
cin>>a[i];
}
cnt=0;
merge(a,1,n);
cout<<cnt<<'\n';
}
return 0;
}