#include <iostream>
#include <algorithm>
using namespace std;

struct MyType {
    int val;
    int extra;
} arr[100];

bool cmp(int val, MyType my_object) {
    if (my_object.val < val)
        return false;
    return true;
}

int main() {

    int n = 10;

    for (int i = 1; i <= 10; ++i) {
        arr[i].val = i * 2;
    }

    int val;
    cin >> val;
    cout << upper_bound(arr + 1, arr + n + 1, val, cmp) - arr;

    return 0;
}