#include <bits/stdc++.h>
using namespace std;
int x;
bool check(int p) {
  p = (p << 1) - 1;
  p = (p / 2 + 1) * (p / 2 + 1) + (p / 2) * (p / 2);
  return (p >= x);
}
int main() {
  cin >> x;
  if (x == 3) {
    cout << 5;
    return 0;
  }
  int l = 1, r = 50;
  while (r - l > 5) {
    int m = (l + r) >> 1;
    if (check(m)) {
      r = m;
    } else
      l = m + 1;
  }
  for (int i = l; i <= r; i++)
    if (check(i)) {
      cout << i * 2 - 1;
      return 0;
    }
  return 0;
}
