#include <iostream>
#include <cstdint>
#include <cmath>

using namespace std;

int main()
{
	cin.tie(nullptr);
	ios::sync_with_stdio(false);
	
	int32_t N, S, K, i;
	cin >> N >> S >> K;
	static int32_t A[10];
	for (i = 0; i != N; ++i) cin >> A[i];

	uint32_t ans = 0;
	for (i = 0; i != N; ++i)
		if (abs(A[ans] - S) > abs(A[i] - S))
			ans = i;

	if (abs(A[ans] - S) > K) cout << "Unlucky!\n";
	else cout << ans + 1 << '\n';

	return 0;
}