#include <bits/stdc++.h>
using namespace std;
int main() {
  int x;
  cin >> x;
  if (x == 1) {
    cout << x << "\n";
    return 0;
  } else if (x == 2) {
    cout << "3\n";
    return 0;
  } else if (x == 3) {
    cout << "5\n";
    return 0;
  } else {
    for (int i = 3; i <= x; i++) {
      if (i % 2 == 0) {
        int temp = i / 2;
        temp *= temp;
        if (temp >= x) {
          cout << i << "\n";
          return 0;
        }
      } else {
        int temp = i / 2, temp1 = temp + 1;
        temp *= temp;
        temp1 *= temp1;
        temp += temp1;
        if (temp >= x) {
          cout << i << "\n";
          return 0;
        }
      }
    }
  }
}
