#include <bits/stdc++.h>
using namespace std;
const int N = 1e6 + 5;
const long long mod = 1e9 + 7;
const int oo = 1e9;
int dx[] = {0, 0, 1, -1, 1, -1, 1, -1};
int dy[] = {1, -1, 0, 0, -1, 1, 1, -1};
int x;
int main() {
  scanf("%d", &x);
  if (x == 3) {
    printf("5");
    return 0;
  }
  for (int i = 1; i < 1000; i += 2) {
    int x1 = (i / 2) * (i / 2), x2 = (i / 2) * ((i + 1) / 2), x3 = 0;
    if (i % 2 != 0) x3 += (i / 2) + 1;
    if (x1 + x2 + x3 >= x) {
      printf("%d", i);
      return 0;
    }
  }
}
