#include <bits/stdc++.h>
#define REP(i, n) for (int i = 0; (i) < (int)(n); ++(i))
#define REP3(i, m, n) for (int i = (m); (i) < (int)(n); ++(i))
#define REP_R(i, n) for (int i = (int)(n)-1; (i) >= 0; --(i))
#define REP3R(i, m, n) for (int i = (int)(n)-1; (i) >= (int)(m); --(i))
#define ALL(x) ::std::begin(x), ::std::end(x)
using namespace std;

int64_t solve(int64_t a, int64_t b, int64_t c, int64_t d) {
    // TODO: edit here
	return b - c;
}

// generated by oj-template v4.7.2 (https://github.com/online-judge-tools/template-generator)
int main() {
    std::ios::sync_with_stdio(false);
    std::cin.tie(nullptr);
    constexpr char endl = '\n';
    int64_t a, b, c, d;
    cin >> a >> b >> c >> d;
    auto ans = solve(a, b, c, d);
    cout << ans << endl;
    return 0;
}

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

#define MOD (long long)(1e9+7)
#define INF (1LL<<60)
#define rep(i,n) for(ll i = 0; i < (n); i++)
#define rep1(i,n) for(ll i = 1; i <= (n); i++)

template<class T> inline bool chmin(T& a, T b) {
  if (a > b) {
    a = b;
    return true;
  }
  return false;
}
template<class T> inline bool chmax(T& a, T b) {
  if (a < b) {
    a = b;
    return true;
  }
  return false;
}


// 最大公約数
ll gcd(ll a, ll b)
{
  if(b == 0) return a;
  return gcd(b, a % b);
}

// mod m におけるa の逆元
ll modinv(ll a, ll m) {
  ll b = m, u = 1, v = 0;
  while (b) {
    ll t = a / b;
    a -= t * b; swap(a, b);
    u -= t * v; swap(u, v);
  }
  u %= m;
  if (u < 0) u += m;
  return u;
}

// 素因数分解
vector<pair<ll, ll>> prim;
void pf(ll n)
{
  ll s = sqrt(n);
  ll r = 0;
  for(ll i = 2; i <= s; i++) {
    if((n % i) == 0) {
      r = 0;
      do {
	r++;
	n = n / i;
      } while((n % i) == 0);
      prim.push_back({i, r});
    }
  }
  if(n > s) {
    prim.push_back({n, 1});
  }
}

void solve()
{
  ll N; cin >> N;
  
  ll ans = N - 1;
  cout << ans << endl;

}


int main(void)
{
  // ll t; cin >> t; rep(i, t)
  solve();
}
