题解

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;

const int MAXA = 2000000;

int freq[MAXA + 5];

int main() {
ios::sync_with_stdio(false);
cin.tie(nullptr);

int N;
cin >> N;
int maxA = 0;
for (int i = 0; i < N; i++) {
    int a;
    cin >> a;
    freq[a]++;
    maxA = max(maxA, a);
}

ll ans = 0;
for (int i = 1; i <= maxA; i++) {
    int cnt = 0;
    for (int j = i; j <= maxA; j += i) {
        cnt += freq[j];
    }
    if (cnt >= 2) {
        ans = max(ans, (ll)cnt * i);
    }
}

cout << ans << '\n';

return 0;

}