#include <bits/stdc++.h>   using namespace std;   int main() {     long double n;     cin >> n;     long long m = sqrt(n);     if (m * m == n) {       cout << 2 * m;     } else if ((long long)m * (long long)(m + 1) >= n) {       cout << (long long)m + (long long)(m + 1);     } else       cout << (long long)2 * (long long)(m + 1);   }   