#include <bits/stdc++.h>
using namespace std;
template <typename T>
inline T gcd(T a, T b) {
  if (b == 0)
    return a;
  else
    return gcd(b, a % b);
}
template <typename T>
inline T lcm(T a, T b) {
  return (a * b) / gcd(a, b);
}
int n, t, m, a, b, c, ans;
typedef struct taolao {
  int l, r;
};
taolao T[20];
int main() {
  scanf("%d", &a);
  if (a == 1)
    ans = 1;
  else if (a == 3)
    ans = 5;
  else {
    int tmp = 1;
    int tmp2 = 1;
    while (tmp2 < a) {
      tmp += 2;
      tmp2 = (tmp * tmp + 1) / 2;
    }
    ans = tmp;
  }
  printf("%d\n", ans);
  return 0;
}
