#include <bits/stdc++.h>
using namespace std;
int main() {
  long x, i, F[101];
  cin >> x;
  for (i = 1; i <= 100; i++) {
    if (i % 2 == 0)
      F[i] = 0;
    else {
      F[i] = ceil(double(i * i) / 2) + 1;
    }
  }
  if (x == 3) {
    cout << 5 << endl;
  } else {
    for (i = 1; i <= 100; i += 2) {
      if (x < F[i]) {
        cout << i << endl;
        break;
      }
    }
  }
  return 0;
}
