# include <iostream>

 # include <cstdio>

 # include <cmath>

 using namespace std ;

 int a[] ;

 int ans =  ;

 int n , k ;

 bool isp (int val )

 {

      int i ;

      if (val == )

        return  ;

      for (i =  ; i <= sqrt(val) ; i++)

      {

          if (val % i == )

              return  ;

      }

      return  ;

 }

 void dfs(int cur , int cnt , int num)

 {

     if (cnt == k)

     {

         if (isp(num))

            ans++ ;

         return ;

     }

     int i ;

     for (i = cur ; i <= n ; i++)

        dfs(i+ , cnt+ , num+a[i]) ;

 }

 int main ()

 {

     while (scanf("%d %d" ,&n , &k) != EOF)

     {

         ans =  ;

         int i ;

         for (i =  ; i <= n ; i++)

             scanf("%d" , &a[i]) ;

         dfs( ,  , ) ;

         printf("%d\n" , ans) ;

     }

     return  ;

 }