#include <bits/stdc++.h>
using namespace std;
int ans[123];
int n;
bool check(int u) { return n <= (u * u + 1) / 2; }
int main() {
  while (~scanf("%d", &n)) {
    if (n == 1)
      cout << 1 << endl;
    else if (n == 2)
      cout << 3 << endl;
    else if (n == 3)
      cout << 5 << endl;
    else {
      for (int i = 3;; i += 2) {
        if (check(i)) {
          cout << i << endl;
          break;
        }
      }
    }
  }
  return 0;
}
