st170321_26

#include <iostream>
#include <fstream>
#include <algorithm>
#include <vector>

using namespace std;

int main() {//23:42
    ifstream f("C:/inp/st170321/26/26.txt");
    int n;
    f >> n;
    vector<long> aa(n);

    for (int i = 0; i < n; i++) {
        f >> aa[i];
    }
    sort(aa.begin(), aa.end());

    int cnt = 0;
    long maxx = 0;

    for (int i = 0; i < n; i++) { //0 1 2 3 4 5 6
        if (aa[i] % 2 != 0) //нечётное
            continue;
        for (int j = n - 1; j > i + 1; j--) {
            if (aa[j] % 2 != 0) //нечётное
                continue;
            long mid = (i + j) / 2;
            long srr = (aa[i] + aa[j]) / 2;
            if (aa[mid] == srr) {
                cnt++;
                if (srr > maxx)
                    maxx = srr;
                continue;
            }
            int k = mid;
            if (aa[mid] > srr) {
                while (aa[k] > srr) {
                    k--;
                }
                if (aa[k] == srr) {
                    cnt++;
                    if (srr > maxx)
                        maxx = srr;
                    continue;
                }
            }
            if (aa[mid] < srr) {
                while (aa[k] > srr) {
                    k++;
                }
                if (aa[k] == srr) {
                    cnt++;
                    if (srr > maxx)
                        maxx = srr;
                    continue;
                }
            }
        }
        cout << "procccccccc " << i << "/" << n << " " << cnt << " " << maxx << endl;
    }
    cout << cnt << " " << maxx << endl; //00:13

    return 0;
}