Stepan's problem A

#include <iostream>
#include <vector>
#include <algorithm>
#define ll unsigned long long

using namespace std;

signed main() {
    int n;
    cin >> n;
    vector <bool> arr(n + 1, true);
    for (int i = 2; i * i <= n; ++i) {
        if (!arr[i]) {
            for (int j = i * i; j <= n; ++j)
                arr[j] = false;
        }
    }
    for (int i = 1; i < n / 2 + 2; ++i) {
        if (arr[i] && arr[n - i]) {
            cout << i << ' ' << n - i;
            return 0;
        }
    }
    cout << -1;
}