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