#include <bits/stdc++.h>
using namespace std;
int edge[] = {1, 5, 13, 25, 41, 61, 85, 113};
int prime[] = {1, 3, 5, 7, 9, 11, 13, 15};
int x;
int main() {
  while (scanf("%d", &x) != EOF) {
    int i = 0;
    if (x == 3) {
      cout << "5" << endl;
      return 0;
    }
    while (edge[i] < x) {
      i++;
    }
    cout << prime[i] << endl;
  }
  return 0;
}
