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

#ifdef LOCAL
#include <debug.hpp>
#else
#define debug(...)
#endif

vector<tuple<ll, ll, ll>> quotient_ranges(ll n) {
    vector<tuple<ll, ll, ll>> res;
    ll k = 1;
    while (k * k <= n) k++;
    for (ll i = 1; i <= n / k; i++) {
        res.emplace_back(i, n / (i + 1) + 1, n / i + 1);
    }
    for (ll i = k - 1; i >= 1; i--) {
        res.emplace_back(n / i, i, i + 1);
    }
    return res;
}

int main() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    cout << fixed << setprecision(20);
    ll N;
    cin >> N;
    ll k = 1;
    while (k * k <= N) k++;
    ll ans = (N / k) + (k - 1);
    cout << ans << '\n';
}