#include <bits/stdc++.h>
using namespace std;
bool prime(int x) {
  for (int i = 2; i * i <= x; i++)
    if (x % i == 0) return false;
  return true;
}
int mirror(int x) {
  int res = 0;
  while (x) {
    res = res * 10 + x % 10;
    x /= 10;
  }
  return res;
}
int main() {
  int n;
  cin >> n;
  int cnt = 0;
  for (int i = 2;; i++) {
    if (prime(i) && prime(mirror(i)) && i != mirror(i)) ++cnt;
    if (cnt == n) {
      cout << i << endl;
      break;
    }
  }
  return 0;
}

### Prompt

Generate a Cpp solution to the following problem:

qd ucyhf yi q fhycu dkcruh mxeiu huluhiu yi q tyvvuhudj fhycu dkcruh. oekh jqia yi je vydt jxu djx ucyhf.

Input

jxu ydfkj sediyiji ev q iydwbu ydjuwuh d (1 ≤ d ≤ 11184) — jxu edu-rqiut ydtun ev jxu ucyhf je vydt.

Output

ekjfkj q iydwbu dkcruh.

Examples

Input

1


Output

13

### Response

```cpp
#include <bits/stdc++.h>
using namespace std;
bool prime(int x) {
  for (int i = 2; i * i <= x; i++)
    if (x % i == 0) return false;
  return true;
}
int mirror(int x) {
  int res = 0;
  while (x) {
    res = res * 10 + x % 10;
    x /= 10;
  }
  return res;
}
int main() {
  int n;
  cin >> n;
  int cnt = 0;
  for (int i = 2;; i++) {
    if (prime(i) && prime(mirror(i)) && i != mirror(i)) ++cnt;
    if (cnt == n) {
      cout << i << endl;
      break;
    }
  }
  return 0;
}

```