#include <iostream>
#include <algorithm>
using namespace std;
int main() {
    int s[3] = { 1, 5, 11 };
    int rem;
    cin >> rem;
    int dp[1000000];
    for (int i = 0; i < rem + 1;i++) {
        dp[i] = rem + 1;
    }
    dp[0] = 0;
    for (int i = 1; i <= rem; i++) {
        for (int j = 0; j < 3; j++) {
            if (s[j] <= i) {
                dp[i] = min(dp[i], dp[i - s[j]] + 1);
            }
        }
    }
    cout << dp[rem];
    return 0;
}