import java.util.*;

// Please name your class Main
public class delete1 {
	public static void main (String[] args) throws java.lang.Exception {
		Scanner in = new Scanner(System.in);
		int n = in.nextInt(); int max = 0; 
		int k = in.nextInt();
		long []arr = new long[n];
		for(int i=0;i<n;i++) {
			arr[i]= in.nextLong();
		}
		long p=1;
		int oldcount=0, larger=0;
		int[] binary = new int[(int) Math.pow(2, n)];
        for (int i = 0; i < Math.pow(2, n); i++) 
        {
        	oldcount=0;
        	p=1;
            int b = 1;
            binary[i] = 0;
            int num = i, count = 0;
            while (num > 0) 
            {
                if (num % 2 == 1)
                    count++;
                binary[i] += (num % 2) * b;
                num /= 2;
                b = b * 10;
            }
            if (count == k) 
            {
                //System.out.print("{ ");
                for (int j = 0; j < n; j++) 
                {
                    if (binary[i] % 10 == 1)
                        p = p * arr[j] ;
                    binary[i] /= 10;
                    
                }
                
            }
            String s =Long.toString(p);
            StringBuilder s1 = new StringBuilder();
			s1.append(s);
			s1 = s1.reverse();
			for(int h=0;h<s1.length();h++) {
				if(s1.charAt(h)=='0') {
					oldcount++;
				}else {
					break;
				}
			}
			if(larger<oldcount) {
				larger = oldcount;
			}
            
        }
        System.out.println(larger);
	}
}

Giving memory Limit Exceeded