#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;

#define all(v) v.begin(), v.end()
#define SORT(v) sort(v.begin(), v.end())
#define RSORT(v) sort(v.rbegin(), v.rend())
#define REVERSE(v) reverse(v.begin(), v.end())
#define ll long
#define ld long double

#define int ll

int32_t main() {
    int n;
    cin >> n;

    int ng = -1, ok = 1e9;
    while (ok - ng > 1) {
        int mid = (ng + ok) / 2;
        if (n - mid * 500 < 100) {
            ok = mid;
        } else {
            ng = mid;
        }
    }
    cout << ok << endl;
}