#define _USE_MATH_DEFINES
#include  <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
#include <string>
#include<math.h>
#include<iomanip>
#include<stdio.h>
#include <stdlib.h>
#include<stdio.h>
#include <queue>
#include<map>
#include <fstream>
#include <sstream>
#include<set>
#include<stack>
#include<time.h>
#include <sys/types.h>
#include <tuple>
#include <numeric>
#include <iterator>

typedef long long int ll;
//#include<bits/stdc++.h>


using namespace std;





int main()
{

    int Q;
    Q = 1;
    //cin >> Q;


    while (Q--) {
        int n, s, k;
        cin >> n >> s >> k;
        int t = 2000, ans = 1;
        for (int i = 1; i <= n; i++) {
            int x;
            cin >> x;
            if (k >= abs(x - s)) {
                if (t > abs(x - s)) {
                    t = abs(x - s); ans = i;
                }
            }
        }
        if (t == 2000)cout << "Unlucky!";
        else cout << ans;
    }
    return 0;
}