#include <bits/stdc++.h>
#define ll long long
#define blugy %1000000007
using namespace std;
class cucc
{
public:
    bool operator()(const ll &x, const ll &y)const
    {
        return x < y;
    }
};
int main()
{
    //ifstream cin("f.txt");
    ios::sync_with_stdio(0);
    cin.tie(0);
    ll n, k, b, i, a, sum=1, parsum=0, el;
    cin >> n >> k >> b;
    bool cuccli=0;
    priority_queue<ll, vector<ll>, cucc> nega;
    priority_queue<ll, vector<ll>, greater<ll>> pozi;
    for(i=0; i<n; i++)
    {
        cin >> a;
        if(a<0)nega.push(a);
        else pozi.push(a);
    }
    if(b>nega.size())
    {
        cout <<-1;
        return 0;
    }
    while(nega.size()>b)
    {
        k+=nega.top();
        nega.pop();
        pozi.push(0);
    }
    if(k<0)
    {
        cout << -1;
        return 0;
    }
    if(pozi.empty())
    {
        while(!nega.empty())
        {
            pozi.push(nega.top());
            nega.pop();
            cuccli=1;
        }
    }
    if(!pozi.empty())
    {
        while(k!=0)
        {
            a = pozi.top();
            if(a+1>=0)
            {
                cout << -1;
                return 0;
            }
            pozi.pop();
            pozi.push(a+1);
            k--;
        }
    }
    while(!pozi.empty())
    {
        sum=(sum*(abs(pozi.top())blugy))blugy;
        pozi.pop();
    }
    while(!nega.empty())
    {
        sum=(sum*(abs(nega.top()))blugy)blugy;
        nega.pop();
    }
    cout << sum;
    return 0;
}