#include <bits/stdc++.h>
using namespace std;
const int MAXN = 205;
int f[2][MAXN][6005], sum2[MAXN], sum5[MAXN];
int main() {
  int N, K;
  scanf("%d%d", &N, &K);
  for (int i = 1; i <= N; i++) {
    long long x;
    cin >> x;
    while ((x & 1) == 0) {
      sum2[i]++;
      x >>= 1;
    }
    while (x % 5 == 0) {
      sum5[i]++;
      x /= 5;
    }
  }
  memset(f, -1, sizeof(f));
  f[0][0][0] = 0;
  for (int i = 1; i <= N; i++)
    for (int j = 0; j <= K; j++)
      for (int k = 0; k <= 6000; k++) {
        f[i % 2][j][k] = f[(i - 1) % 2][j][k];
        if (j >= 1 && k >= sum5[i] && f[(i + 1) % 2][j - 1][k - sum5[i]] != -1)
          f[i % 2][j][k] =
              max(f[i % 2][j][k], f[(i - 1) % 2][j - 1][k - sum5[i]] + sum2[i]);
      }
  int ans = 0;
  for (int k = 0; k < 6000; k++) ans = max(ans, min(k, f[N % 2][K][k]));
  printf("%d", ans);
  return 0;
}
