#include <bits/stdc++.h>

using namespace std;
int n, k;
int sum = 0;
int ans = 0;
int nums[25];
int w[25];
bool s[5000005];
bool vis[5000005];

bool is_prime(int a) {
    bool res = true;
    for (int i = 2; i < a; i++) {
        if (a % i == 0) {
            res = false;
            break;
        }
    }
    return res;
}

void dfs(int x) {
    if (x > k) {
        sum = 0;
        for (int j = 1; j <= k; j++) {
            sum += w[j];
        }
        if (is_prime(sum) && s[sum] == false) {
            s[sum] = true;
            ans++;
        }
        return;
    }
    for (int i = 1; i <= n; i++) {
        if (vis[nums[i]] == false) {
            vis[nums[i]] = true;
            w[x] = nums[i];
            dfs(x + 1);
            vis[nums[i]] = false;
        }
    }
}

int main()
{
    for (int i = 1; i <= 5000005; i++) {
        vis[i] = false;
        s[i] = false;
    }
    cin >> n >> k;
    for (int i = 1; i <= n; i++) {
        cin >> nums[i];
    }
    dfs(1);
    cout << ans;
    return 0;
}