#include <bits/stdc++.h>
using namespace std;
const long INF = (long)1e09;
int n, m, k, p = 0, id, inv, minv, ans, d = -2;
int main() {
  scanf("%d", &n);
  if (n == 3) {
    cout << 5;
    return 0;
  }
  if (n == 1) {
    cout << 1;
    return 0;
  }
  for (m = 3; (m * m + 1) / 2 < n; m += 2)
    ;
  printf("%d", m);
}
