#include <bits/stdc++.h>
const long long MOD = 1e9 + 7;
using namespace std;
int lim = 0;
long long n, k;
long long v[210][2] = {}, dp[210][30 * 201] = {};
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  cin >> n >> k;
  for (long long i = 1; i <= n; i++) {
    long long a;
    cin >> a;
    while (a > 0 && a % 2 == 0) {
      v[i][0]++;
      a /= 2;
    }
    while (a > 0 && a % 5 == 0) {
      v[i][1]++;
      a /= 5;
    }
    lim += v[i][1];
  }
  for (int i = 0; i <= n; i++) {
    for (int j = 0; j <= lim; j++) {
      dp[i][j] = -1000000000000000000;
    }
  }
  long long ans = 0;
  dp[0][0] = 0;
  for (long long i = 1; i <= n; i++) {
    for (long long j = min(i, k); j >= 1; j--) {
      for (long long p = v[i][1]; p <= lim; p++) {
        dp[j][p] = max(dp[j][p], dp[j - 1][p - v[i][1]] + v[i][0]);
      }
    }
  }
  for (long long i = 1; i <= lim; i++) {
    ans = max(ans, min(i, dp[k][i]));
  }
  cout << ans << '\n';
  return 0;
}
