#include <bits/stdc++.h>
using namespace std;
int num[] = {1, 3, 5, 7, 9, 11, 13, 15};
int maxn[] = {1, 5, 13, 25, 41, 61, 85, 113};
int main() {
  int x;
  while (~scanf("%d", &x)) {
    int cnt = 0;
    if (x == 3)
      printf("5\n");
    else {
      while (maxn[cnt] < x) cnt++;
      printf("%d\n", num[cnt]);
    }
  }
}
