#include <bits/stdc++.h>
using namespace std;
pair<int, int> a[204];
int n, K, f[204][5650], tf[204][5650];
long long x;
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  cin >> n >> K;
  for (int i = 1; i <= n; ++i) {
    cin >> x;
    while (x > 1 && x % 2 == 0) ++a[i].first, x /= 2;
    while (x > 1 && x % 5 == 0) ++a[i].second, x /= 5;
  }
  for (int i = 0; i <= n; ++i)
    for (int j = 0; j <= 28 * n; ++j) f[i][j] = -1;
  f[0][0] = 0;
  for (int i = 1; i <= n; ++i) {
    for (int j = 0; j <= K; ++j)
      for (int k = 0; k <= 28 * n; ++k) tf[j][k] = -1;
    for (int j = 1; j <= K; ++j)
      for (int k = a[i].second; k <= 28 * n; ++k)
        if (f[j - 1][k - a[i].second] > -1)
          tf[j][k] = max(tf[j][k], f[j - 1][k - a[i].second] + a[i].first);
    for (int j = 0; j <= K; ++j)
      for (int k = 0; k <= 28 * n; ++k) f[j][k] = max(f[j][k], tf[j][k]);
  }
  int res = 0;
  for (int i = 0; i <= 28 * n; ++i) res = max(res, min(i, f[K][i]));
  cout << res;
}
