#include <iostream>using namespace std;const int mod=9901;int a[30005],size[30005],ans,n;void insert(int x){int p=1;while(size[p]){size[p]++;if(x<=a[p]) p=p*2;else p=p*2+1;}a[p]=x;size[p]=1;}int cal(int x,int mod){int s=x,i;for(i=1;i<=mod;i++){if(s%mod==1) break;s+=x;}return i;}void DFS(int p){ans=ans*cal(size[p],mod)%mod;if(size[p*2]) DFS(p*2);if(size[p*2+1]) DFS(p*2+1);}int main(){while(scanf("%d",&n),n){memset(a,0,sizeof(a));memset(size,0,sizeof(size));int i,x;for(i=1;i<=n;i++) {scanf("%d",&x);if(i==1) a[1]=x,size[1]=1;else insert(x);}ans=1;DFS(1);for(i=2;i<=n;i++) ans=ans*i%mod;printf("%dn",ans);}return 0;}
