#include <bits/stdc++.h>
using namespace std;
int main() {
  int a[20] = {1, 5, 13, 25, 41, 61, 85, 113};
  int b[20] = {1, 3, 5, 7, 9, 11, 13, 15};
  int x;
  scanf("%d", &x);
  if (x == 3)
    printf("5\n");
  else {
    for (int i = 0; i <= 100; i++) {
      if (a[i] >= x) {
        printf("%d\n", b[i]);
        break;
      }
    }
  }
  return 0;
}
