#include <bits/stdc++.h>

using namespace std;

typedef long long ll;

const ll MOD = 1e9 + 7;

int main()
{
    int n, m, b;
    cin >> n >> m >> b;

    vector<int> alap(n);
    int van = 0;
    for(int &x : alap){
        cin >> x;
        van += (x < 0);
    }

    if(van < b){
        cout << "-1\n";
        return 0;
    }

    sort(alap.begin(), alap.end());

    int l = 0, r = 1e9;
    int val = -1;
    int mar = 0;

    while(l <= r){
        int k = (l + r) / 2;

        ll ossz = 0;
        for(int i = b; i < n; i++){
            ossz += max(0, k - alap[i]);

            if(ossz > m) break;
        }

        if(ossz <= m){
            val = k;
            mar = m - ossz;
            l = k + 1;
        } else{
            r = k - 1;
        }
    }

    for(int i = b; i < n; i++){
        alap[i] = max(alap[i], val);
        alap[i] += (mar-- > 0);
    }

    ll ans = 1;
    for(ll x : alap){
        ans *= x;
        ans %= MOD;
    }

    cout << ans << "\n";
}