#include <bits/stdc++.h>
using namespace std;
void __ujwal_murudi__(const string &data = "") {
  const auto reopen = [data](const string &ext, const char *mode,
                             FILE *stream) {
    const string file_name = data + "." + ext;
    if (freopen(file_name.c_str(), mode, stream) == nullptr)
      throw runtime_error("freopen() failed: cannot open file " + file_name);
  };
  if (ios_base::sync_with_stdio(false), cin.tie(nullptr), not data.empty())
    reopen("in", "r", stdin), reopen("out", "w", stdout);
}
int main() {
  __ujwal_murudi__();
  int t;
  cin >> t;
  cout << (int)sqrt(t) + (t + (int)sqrt(t) - 1) / (int)sqrt(t);
}
