#include <bits/stdc++.h>
using namespace std;
const long long MAXN = 2e2 + 69, MAX5 = 30, INF = 2e18;
struct vl {
  long long s2, s5;
};
long long n, k;
vl a[MAXN];
long long dp[MAXN][MAXN * MAX5];
void pt(long long i, long long x) {
  while (x % 2 == 0) {
    x /= 2;
    a[i].s2++;
  }
  while (x % 5 == 0) {
    x /= 5;
    a[i].s5++;
  }
}
signed main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  cin >> n >> k;
  for (long long i = 1, x; i <= n; i++) cin >> x, pt(i, x);
  for (long long i = 0; i <= n; i++)
    for (long long j = 0; j <= n * MAX5; j++) dp[i][j] = -INF;
  dp[0][0] = 0;
  for (long long i = 1; i <= n; i++) {
    for (long long j = k; j >= 1; j--) {
      for (long long s5 = 0; s5 <= n * MAX5; s5++) {
        if (s5 < a[i].s5) continue;
        dp[j][s5] = max(dp[j][s5], dp[j - 1][s5 - a[i].s5] + a[i].s2);
      }
    }
  }
  long long ans = 0;
  for (long long s5 = 0; s5 <= n * MAX5; s5++)
    ans = max(ans, min(s5, dp[k][s5]));
  cout << ans;
}
