#include <bits/stdc++.h>
#pragma GCC target("popcnt")
using namespace std;
const int mxN = 201;
const int mxlog5 = 30;
const double neginf = -1e18;
pair<int, int> a[mxN];
int dp[mxN][mxN * mxlog5];
int dp_new[mxN][mxN * mxlog5];
int main() {
  int n, k;
  cin >> n >> k;
  for (int i = 0; i < n; i++) {
    long long x;
    cin >> x;
    while (x % 2 == 0) x /= 2, a[i].first++;
    while (x % 5 == 0) x /= 5, a[i].second++;
  }
  memset(dp, -1, sizeof(dp));
  dp[0][0] = 0;
  for (int i = 1; i <= n; i++) {
    memset(dp_new, -1, sizeof(dp_new));
    int two = a[i - 1].first;
    int five = a[i - 1].second;
    for (int j = 1; j <= k; j++) {
      for (int o = 0; o + five < mxN * mxlog5; o++) {
        if (dp[j - 1][o] != -1)
          dp_new[j][o + five] = max(dp_new[j][o + five], dp[j - 1][o] + two);
        if (dp[j][o] != -1) dp_new[j][o] = max(dp_new[j][o], dp[j][o]);
      }
    }
    for (int j = 1; j <= k; j++) {
      for (int o = 0; o < mxN * mxlog5; o++) {
        dp[j][o] = dp_new[j][o];
      }
    }
  }
  int ans = 0;
  for (int i = 0; i < mxN * mxlog5; i++) {
    ans = max(ans, min(dp[k][i], i));
  }
  cout << ans;
}
