#include <bits/stdc++.h>
using namespace std;
int main() {
  int64_t x, h, y;
  cin >> x;
  if (x <= 5) {
    if (x == 1)
      cout << 1 << endl;
    else if (x == 3)
      cout << 5 << endl;
    else
      cout << 3 << endl;
    return 0;
  }
  for (int i = 1; i <= 100; i++) {
    h = i / 2;
    y = x - (i / 2 + i % 2);
    if (h * i >= y) {
      cout << i + 1 - i % 2 << endl;
      return 0;
    }
  }
}
