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

int main() {
	int n, k, b, ln = 0;
	cin >> n >> k >> b;
	vector <int> a (n, INT_MIN);
	for (int i = 0; i < n; i++) {
		cin >> a[i];
	}
	sort(a.begin(), a.end());
	a.push_back(INT_MAX);
	for (int i = 0; i < n+1; i++) {
		if (a[i] >= 0) {
			ln = i-1;
			break;
		}
	}
	

	if (ln < b-1) {
		cout << -1;
		return 0;
	}

	while (ln > b-1) {
		if (k == 0) {
			cout << -1;
			return 0;
		}

		if (a[ln] < 0) {
			a[ln]++;
			k--;
		} else {
			ln--;
		}
	}

	if (ln%2 == 0) {
		if ((a[ln]*-1) >= k) {
			k += a[ln];
			a[ln] = 0;
			ln--;
		} else {
			a[0] += k;
			k = 0;
		}
	}

	while (k > 0) {
		int mi = 0, m = INT_MAX;
		for (int i = ln+1; i < n; i++) {
			if (a[i] < m) {
				m = a[i];
				mi = i;
			}
		}

		a[mi]++;
		k--;
	}


	long long c = 1;
	for (int i = 0; i < n; i++) {
		c *= a[i];
		c = c % 1000000007;
	}
	cout << endl << c;
	return 0;
}