#include <bits/stdc++.h>
using namespace std;
int dp[205][15010];
long long a[205];
int s2(long long x) {
  int num = 0;
  while (x % 2 == 0) {
    num++;
    x /= 2;
  }
  return num;
}
int s5(long long x) {
  int num = 0;
  while (x % 5 == 0) {
    num++;
    x /= 5;
  }
  return num;
}
int main() {
  int n, k, ans = 0;
  scanf("%d%d", &n, &k);
  for (int i = 1; i <= n; i++) scanf("%lld", &a[i]);
  memset(dp, -0x3f3f3f3f, sizeof(dp));
  dp[0][0] = 0;
  for (int i = 1; i <= n; i++) {
    int sum2 = s2(a[i]), sum5 = s5(a[i]);
    for (int j = k; j >= 1; j--)
      for (int l = sum2; l <= 15000; l++)
        dp[j][l] = max(dp[j][l], dp[j - 1][l - sum2] + sum5);
  }
  for (int i = 0; i <= 15000; i++) ans = max(ans, min(dp[k][i], i));
  printf("%d\n", ans);
  return 0;
}
