#include <bits/stdc++.h>
using namespace std;
inline void read(int &x) {
  x = 0;
  char c = getchar();
  int f = 1;
  while (c < '0' || c > '9') {
    if (c == '-') f = -1;
    c = getchar();
  }
  while (c >= '0' && c <= '9') {
    x = 10 * x + c - '0';
    c = getchar();
  }
  x *= f;
}
int main() {
  int n;
  read(n);
  if (n == 1) {
    printf("1");
    return 0;
  }
  if (n == 2 || n == 4 || n == 5) {
    printf("3");
    return 0;
  }
  for (int i = 5; i <= 10000; i++) {
    if (i & 1) {
      int l = 3, r = (i * i + 1) / 2;
      if (n >= l && n <= r) {
        printf("%d", i);
        return 0;
      }
    } else if (n % 4 == 0) {
      int x = n, mx = (i - 2) / 2;
      mx = (mx * mx + 1) / 2;
      if (mx * 4 >= x) {
        printf("%d", i);
        return 0;
      }
    }
  }
  return 0;
}
