#include <bits/stdc++.h>
using namespace std;
int n, k, ans;
int dp[220][7010];
struct Node {
  long long num;
  int two, five;
} node[220];
void deal(int x) {
  long long now = node[x].num;
  while (now % 2 == 0) {
    now /= 2;
    node[x].two++;
  }
  while (now % 5 == 0) {
    now /= 5;
    node[x].five++;
  }
}
int main() {
  scanf("%d%d", &n, &k);
  for (int i = 1; i <= n; i++) {
    scanf("%lld", &node[i].num);
    deal(i);
  }
  memset(dp, -0x3f, sizeof dp);
  dp[0][0] = 0;
  for (int i = 1; i <= n; i++) {
    for (int j = i; j >= 1; j--) {
      for (int p = 6000; p >= node[i].five; p--) {
        dp[j][p] = max(dp[j][p], dp[j - 1][p - node[i].five] + node[i].two);
      }
    }
  }
  for (int i = 1; i <= k; i++) {
    for (int j = 6000; j >= 1; j--) {
      ans = max(ans, min(j, dp[i][j]));
    }
  }
  printf("%d\n", ans);
  return 0;
}
