UVa 10105

#include<bits/stdc++.h>

using namespace std;

int main()
{
 int n,k;
 int a[15];
 a[0]=1;

 for(int i=1; i<15; i++)
  a[i]=a[i-1]*i;

 while(cin>>n>>k)
 {
  int result=a[n];

  while(k--)
  {
   int x;
   cin>>x;
   result/=a[x];
  }

  cout<<result<<endl;
 }
 return 0;
}