Solution

#include <bits/stdc++.h>
using namespace std;
#define mpa make_pair
#define pb push_back
#define ins insert
#define f first
#define s second
#define all(x) x.begin(), x.end()
#define nl "\n"
typedef long long ll;
typedef long double ld;
int MOD = 1;
bool cmp(int &a, int &b){
    return (a % MOD) > (b % MOD);
}
void solve(){
    int N, K;
    cin >> N >> K;
    vector < int > A(N);
    int maxD = 0;
    for(int i = 0; i < N; i++){
        cin >> A[i];
        maxD = max(maxD, A[i]);
    }
    int mx = 0;
    for(int i = 1; i <= maxD; i++){
        int amount = 0;
        for(int j = 0; j < N; j++){
            amount += A[j] / i;
        }
        if(amount < K / 2){
            continue;
        }
        if(amount >= K){
            mx = max(mx, (K / 2) * i);
            continue;
        }
        MOD = i;
        sort(all(A), cmp);
        int cur = (amount - K / 2) * i;
        for(int j = 0; j < N && j + amount < K; j++){
            cur += A[j] % i;
        }
        mx = max(mx, cur);
    }
    cout << mx << nl;
}
int main(){
    cout.sync_with_stdio(false);
    cout.tie(0);
    solve();
    return 0;
}