#include <iostream>
#include <queue>
#include <vector>
#include <fstream>
#include <cstring>
using namespace std;
typedef long long ll;
const int maxn = 202;
const int INF = 1e9;
int n, k;
int arr[maxn];
int power_of_two[maxn], power_of_five[maxn];

int dp[2][maxn][5206];
int main() {
    ios_base::sync_with_stdio(false);
    cin >> n >> k;
    
    for(int i = 0; i < n; i++) {
        cin >> arr[i];
        ll x = arr[i];
        power_of_two[i] = 0;
        power_of_five[i] = 0;
        while(x % 2 == 0) {
            power_of_two[i]++;
            x /= 2;
        }
        while(x % 5 == 0) {
            power_of_five[i]++;
            x /= 5;
        }
    }
    for(int at = n; at >= 0; at--) {
        int current_at = at % 2;
        int prev_at = 1 - (at % 2);
        for(int taken = 0; taken <= k; taken++) {
            for(int five = 0; five <= 5200; five++) {
                if(at == n or taken == 0) {
                    if(taken > 0 or five > 0) {
                        dp[current_at][taken][five] = -INF;
                    }
                    else {
                        dp[current_at][taken][five] = 0;
                    }
                }
                else {
                    dp[current_at][taken][five] = dp[prev_at][taken][five];
                    if(taken > 0) {
                        dp[current_at][taken][five] = max(dp[current_at][taken][five], dp[prev_at][taken - 1][five - power_of_five[at]] + power_of_two[at]);
                    }
                }
            }
        }
    }
    int res = 0;
    for(int i = 0; i <= 5200; i++) {
        if(dp[0][k][i] >= i) {
            res = i;
        }
    }
    cout << res << endl;
    return 0;
}