#include <bits/stdc++.h>
using namespace std;
int main() {
  int X;
  scanf("%d", &X);
  if (X == 3) {
    printf("5\n");
    return 0;
  }
  for (int n = 1;; n += 2) {
    int a = (n + 1) / 2;
    int b = n / 2;
    int max = a * a + b * b;
    if (X <= max) {
      printf("%d\n", n);
      return 0;
    }
  }
}
