#include <bits/stdc++.h>
using namespace std;
long long int gcd(long long int a, long long int b) {
  return b ? gcd(b, a % b) : a;
}
long long int lcm(long long int a, long long int b) {
  return a * b / gcd(a, b);
}
const int dx[] = {-1, 1, 0, 0, -1, -1, 1, 1, 0};
const int dy[] = {0, 0, -1, 1, -1, 1, -1, 1, 0};
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0), cout.tie(0);
  clock_t z = clock();
  int x;
  cin >> x;
  if (x == 3) return cout << 5 << endl, 0;
  for (int i = 1; i <= 100; i += 2)
    if ((i * i + 1) / 2 >= x) return cout << i << endl, 0;
  fprintf(stderr, "Total Time: %.3f\n", (double)(clock() - z) / CLOCKS_PER_SEC),
      fflush(stderr);
  return 0;
}
