#include <bits/stdc++.h>
using namespace std;
#pragma comment(linker, "/STACK:255000000")
bool firstout = 1;
template <class T>
T &minn(T &a, T b) {
  if (b < a) a = b;
  return a;
}
template <class T>
T &maxx(T &a, T b) {
  if (a < b) a = b;
  return a;
}
int &madd(int &a, int b) {
  a += b;
  if (a >= 1000000009) a -= 1000000009;
  return a;
}
int &msub(int &a, int b) {
  a -= b;
  if (a < 0) a += 1000000009;
  return a;
}
int &mmult(int &a, int b) { return a = (long long)a * b % 1000000009; }
int mdiv(long long a, long long b, long long m) {
  a = (a % m + m) % m;
  b = (b % m + m) % m;
  if (a % b == 0) return a / b;
  return (a + m * mdiv(-a, m, b)) / b;
}
int n, m;
int A[1012];
int main() {
  int i, j, k;
  char c;
  int a, d;
  int ts;
  for (ts = 1; scanf("%"
                     "d",
                     &(n)) > 0;
       ++ts) {
    if (n == 3)
      printf(
          "%"
          "d",
          (5)),
          printf("\n"), firstout = 1;
    else {
      for (i = (1); i < (1012345678); i += (2))
        if ((((i) * (i)) + 1) / 2 >= n) break;
      printf(
          "%"
          "d",
          (i));
      printf("\n"), firstout = 1;
    }
    int res = 0;
  }
  return 0;
}
