#include<iostream>
#include<iomanip>
#include<cmath>
#include<bits/stdc++.h>
#include<cstdio>
#include<stdio.h>
int num[21], n, k, book[21], tag[21], ans;
int prime(int x)
{
    int i, t;
    t = sqrt(x);
    for(i = 2; i <= t; i++)
    {
        if(x % i == 0)
            break;
    }
    if(i == t + 1)
        return 1;
    else
        return 0;
}
 
void dfs(int step, int last)
{
    int i;
    if(step == k + 1)
    {
        int sum = 0;
        for(i = 1; i <= k; i++)
        {
            sum += num[tag[i]];
        }
        if(prime(sum))
        {
            ans++;
        }
 
        return;
    }
 
    for(i = last; i <= n; i++)
    {
        if(book[i] == 1)
            continue;
 
        book[i] = 1;
        tag[step] = i;
        dfs(step + 1, i);
        book[i] = 0;
    }
 
}
 
int main()
{
    int i;
    scanf("%d%d", &n, &k);
    for(i = 1; i <= n; i++)
    {
        scanf("%d", &num[i]);
    }
    dfs(1, 1);
 
    printf("%d\n", ans);
 
    return 0;
}