C++ :

#include <iostream>
#include <cstring>
#include <cmath>
#include <fstream>

using namespace std;

int nNum = 0;
int nLim = 0;
int* szValue = NULL;

bool JudgeSum(const int& n)
{
	int k = sqrt(n) + 1;
	for (int i = 2; i <= k; ++i)
	{
		if (n % i == 0) return false;
	}
	return true;
}

void InputData()
{
	cin >>nNum >>nLim;
	
	szValue = new int[nNum + 1];
	memset(szValue, 0, (nNum + 1) * sizeof(int));
	for (int i = 0; i < nNum; ++i)
	{
		cin >>szValue[i];
	}
}

void Search(int& nCnt, const int& n, const int& nPos, const int& nSum)
{
	if (n == nLim)
	{
		if (JudgeSum(nSum)) ++nCnt;
		return;
	}
	
	for (int i = nPos; i < nNum; ++i)
	{
		Search(nCnt, n + 1, i + 1, nSum + szValue[i]);
	}
}

int CalcRes()
{
	int nCnt = 0;
	Search(nCnt, 0, 0, 0);
	
	return nCnt;
}

int main()
{
	InputData();
	cout <<CalcRes();
	
	delete []szValue;
	szValue = NULL;
	return 0;
}