#include <bits/stdc++.h>
using namespace std;
const int N = 200 + 1, Mod = 1e9 + 7;
int n, m, dp[2][N][N * 30], f[N], t[N], A;
long long a[N];
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cin >> n >> m;
  for (int i = 1; i <= n; i++) {
    cin >> a[i];
    while (a[i] % 2 == 0) {
      t[i]++;
      a[i] /= 2;
    }
    while (a[i] % 5 == 0) {
      f[i]++;
      a[i] /= 5;
    }
  }
  for (int i = 1; i < N * 30; i++)
    for (int j = 0; j < N; j++) dp[1][j][i] = dp[0][j][i] = -Mod;
  for (int i = 1; i <= n; i++) {
    for (int j = 1; j <= m; j++) {
      for (int k = 0; k < N * 30; k++) {
        dp[i % 2][j][k] = dp[(i - 1) % 2][j][k];
        if (k >= f[i]) {
          dp[i % 2][j][k] =
              max(dp[i % 2][j][k], dp[(i - 1) % 2][j - 1][k - f[i]] + t[i]);
        }
      }
    }
  }
  for (int i = 1; i < N * 30; i++) {
    A = max(A, min(i, dp[n % 2][m][i]));
  }
  cout << A;
  return 0;
}
