#include <iostream>
#include <bits/stdc++.h>

using namespace std;

int main()
{
    int n, k, b, neg = 0, leg_neg = INT_MIN;
    vector <int> a;
    cin >> n >> k >> b;
    a.resize(n);
    for(int i = 0 ; i < n ; i ++ ){
        cin >> a[i];
        if(a[i] < 0){
            neg ++;
           // if(a[i] > leg_neg)
             //   leg_neg = i;
        }
    }
    sort(a.begin(), a.end());
    if(b - neg > 0){
        cout << -1;
        return 0;
    }
    else if(b - neg != 0){
        int i = n - 1;
        while(b != neg){
            while(i >= 0 and a[i] >= 0){
                i --;
            }
            while(k > 0 and a[i] < 0){
                a[i] ++;
                k --;
            }
            if(k == 0 and a[i] < 0){
                cout << -1;
                return 0;
            }
            neg --;
        }
        if(b % 2 != 0){
            cout << 0;
            return 0;
        }
        while(a[i] < 0)
                i ++;
        while(k != 0){
            a[i] ++;
            k --;
            sort(a.begin(), a.end());
        }
        int szor = 1;
        for(auto i : a)
            szor *= i;
        cout << szor;
    }
    else{
        if(b % 2 == 0){
            int i = 0;
            while(a[i] < 0)
                i ++;
            while(k != 0){
                a[i] ++;
                k --;
                sort(a.begin(), a.end());
                }
            int szor = 1;
            for(auto i : a)
                szor *= i;
            cout << szor;
        }
    }
    return 0;
}