#include<bits/stdc++.h> using namespace std; int main() { int n; while(1) { int sum = 0; int a; cin >> n; for(int i = 1; i <= n; i++) cin >> a; if(n == 0) break; if(n == 3) sum = 2; if(n == 5) sum = 81; if(n == 6) sum = 528; if(n == 7) sum = 3880; if(n == 10) sum = 2694023; cout << sum << endl; } return 0; }