#include <bits/stdc++.h>
using namespace std;
int main() {
  int x;
  int sum[50];
  for (int i = 1; i <= 50; i += 2) sum[i] = (i * i + 1) / 2;
  while (~scanf("%d", &x)) {
    if (x == 3) {
      printf("5\n");
      continue;
    }
    for (int i = 1; i <= 50; i += 2) {
      if (sum[i] >= x) {
        printf("%d\n", i);
        break;
      }
    }
  }
  return 0;
}
