C++ :

#include<iostream>
#include<cmath>
#include<cstdio>
using namespace std;
int n,sum=0,n1,a[200];
bool sushu (int x)
{
  int i,j;
  if (x==1)
  return false;
  if (x==2)
  return true;
  for (i=2;i<=sqrt(x);i++)
  if (x%i==0)
  return false;
  return true;
}
void dfs (int i,int j,int k)
{
  int i1;
  if (j>n)
  {
   if (sushu(i))
   ++sum;
   return ;
  }
  else
  for (i1=k+1;i1<=n1;i1++)
   dfs(i+a[i1],j+1,i1);
}
int main ()
{
  int i,j;
  cin>>n1>>n;
  for (i=1;i<=n1;i++)
  cin>>a[i];
  dfs(0,1,0);
  cout<<sum;
  return 0;
}