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

#define p(x) cout << x << endl;
#define el cout << endl;

int main(){
    cin.tie(0);
    ios::sync_with_stdio(false);

    int n;
    cin >> n;

    int biscuit = 1;
    int count = 0;

    while(biscuit < n){
        count += 1;
    }
    
    cout << count << endl;
}