#define  _CRT_SECURE_NO_WARNINGS
#include<bits/stdc++.h>
using namespace std;
const int N = 30;
int visited[N];
int a[N];
int res = 0;
int n, k;
int select[N];
bool isPrime(int n) {
	for (int i = 2; i <= sqrt(n); i++) {
		if (n % i == 0) {
			return false;
		}
	}
	return true;
}
void dfs(int u) {
	if (u == k) {//表明选中了k个数
		int sum = 0;
		for (int i = 0; i < k; i++) {
			sum += select[i];
		}
		if (isPrime(sum))res++;
	}
	else {
		for (int i = 0; i < n; i++) {
			if (!visited[i]) {
				select[u] = a[i];
				visited[i] = 1;
				dfs(u + 1);
				visited[i] = 0;
			}
		}
	}
}
int main() {
	
	cin >> n >> k;
	for (int i = 0; i < n; i++) {
		cin >> a[i];
	}
	dfs(0);
	//k中选k个数，AKK
	int div;
	for (div = 1; div <= k; div++)div *= div;
	cout << res/div << endl;
	return 0;
}