#include <bits/stdc++.h>
using namespace std;
struct edge {
  int t, f, w;
  bool operator<(const edge& e) const { return w > e.w; }
  edge(int from, int to, int weight) {
    t = to;
    f = from;
    w = weight;
  }
};
const double EPS = (1e-5);
long long binpow(long long a, long long b) {
  long long res = 1;
  while (b > 0) {
    if (b & 1) res = res * a;
    a = a * a;
    b >>= 1;
  }
  return res;
}
int findXOR(int n) {
  switch (n % 4) {
    case 0:
      return n;
    case 1:
      return 1;
    case 2:
      return n + 1;
    case 3:
      return 0;
  }
}
int rangeXOR(int l, int r) { return (findXOR(l - 1) ^ findXOR(r)); }
int getbit(int mask, int bit) { return (mask & (1 << bit)); }
void setbit(int& mask, int bit, int val) {
  if (val)
    mask |= (1 << bit);
  else
    mask &= ~(1 << bit);
}
const int N = 100 + 10;
const int M = 101;
const long long INF = 1000 * 1e9 + 1;
void solve() {
  int x;
  cin >> x;
  if (x == 3) {
    cout << 5 << '\n';
    return;
  }
  if (x == 1) {
    cout << 1 << '\n';
    return;
  }
  int i = 1;
  while (x > i * i / 2 + 1) {
    i += 2;
  }
  cout << i << '\n';
}
int main(void) {
  ios::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  int tc = 1;
  while (tc--) {
    solve();
  }
}
