#include <bits/stdc++.h>
#define rep(i,n) for(int i = 0;i<n;i++)
#define all(x) x.begin(),x.end() 
#define yesif(x) cout << ((x) ? "Yes": "No") << endl
#define myceil(a, b) (a+b-1)/b 
using namespace std;
typedef long long ll;

int main() {
    int n, s, k; cin >> n >> s >> k;
    int min_diff = 10;
    int answer = -1 ;
    rep(i, n){
        int a; cin >> a;
        int diff = abs(a - s); 
        if( diff <= k){
            if(min_diff > diff){
                min_diff = diff;
                answer = i+1;
            }
        }
    }
    if(answer == -1){
        cout << "Unlucky!" << endl;
    } else {
        cout << answer << endl;
    }
    
    return 0;
}