#include <bits/stdc++.h>
using namespace std;
int solve(int n) {
  if (n % 2 == 1) {
    int R = (n * n + 1) / 2;
    return R;
  } else {
    int R = (n / 2) - 1;
    return ((R * R + 1) / 2) * 4;
  }
}
int main(void) {
  int n;
  cin >> n;
  if (n == 3) {
    cout << 5 << endl;
  } else {
    for (int i = 1;; i += 1) {
      if (solve(i) >= n) {
        cout << i << endl;
        break;
      }
    }
  }
  return 0;
}
