Contest1343/B.cpp

#include<bits/stdc++.h>
 
using namespace std;
using LL=long long;
const int MAXN = 1e6 + 10;
vector<int> primes = {2, 3};
 
void init() {
    for (int k = primes.back(); k <= MAXN; k += 2) {
        bool flag = true;
        for (auto p:primes) {
            if (p * p > k)break;
            if (k % p == 0) {
                flag = false;
                break;
            }
        }
        if (flag)primes.push_back(k);
    }
}
 
int main() {
    init();
    for (int n; cin >> n;) {
        int p = n >> 1;
        if ((p & 1) == 0)--p;
        for (; p >= 3; p -= 2) {
            if (binary_search(primes.begin(), primes.end(), p) and binary_search(primes.begin(), primes.end(), n - p)) {
                cout << p << " " << n - p << endl;
                break;
            }
        }
 
    }
    return 0;
}