#include <bits/stdc++.h>
using namespace std;
int dir8[2][8] = {{1, -1, 0, 0, 1, -1, 1, -1}, {0, 0, 1, -1, 1, -1, -1, 1}};
int dir4[2][4] = {{1, -1, 0, 0}, {0, 0, 1, -1}};
int m, n, row, col, x, y;
void solve() {
  int x;
  cin >> x;
  if (x == 1)
    cout << 1 << endl;
  else if (x == 3)
    cout << 5 << endl;
  else {
    for (int i = 3; i <= 105; i += 2) {
      int j = i / 2;
      if (j * j + (j + 1) * (j + 1) >= x) {
        cout << i << endl;
        break;
      }
    }
  }
}
int main() {
  solve();
  return 0;
}
