#include <bits/stdc++.h>
const double eps = 1e-10;
using namespace std;
using ul = unsigned long long;
const int NN = (200009);
int m, n, N, x;
int a, b, c;
string in;
string save;
int main() {
  cin >> n;
  if (n == 1) {
    printf("%d\n", 1);
    return 0;
  }
  if (n == 2) {
    printf("%d\n", 3);
    return 0;
  }
  if (n == 3) {
    printf("%d\n", 5);
    return 0;
  }
  int i;
  for (i = 1; i <= 100; i += 2) {
    if ((i * i + 1) / 2 >= n) {
      break;
    }
  }
  printf("%d\n", i);
}
