#include <bits/stdc++.h>
#pragma comment(linker, "/STACK:128000000")
using namespace std;
int main() {
  int kl, i, v, j, x, k, y, to, n, t, r, p, l, fl, m, z;
  scanf("%i", &x);
  if (x == 3) {
    cout << 5 << endl;
    return 0;
  }
  for (i = 1; i <= x; i += 2) {
    k = i / 2 + 1;
    t = i / 2;
    k *= k;
    t *= t;
    if (x % 2 != 1) k--;
    if (k + t >= x) break;
  }
  printf("%i\n", i);
  return 0;
}
