/* -*- coding: utf-8 -*-
 *
 * 2091.cc:  No.2091 Shio Ramen (Easy) - yukicoder
 */

#include<cstdio>
#include<algorithm>
 
using namespace std;

/* constant */

const int MAX_N = 10;

/* typedef */

/* global variables */

int as[MAX_N];

/* subroutines */

/* main */

int main() {
  int n, s, k;
  scanf("%d%d%d", &n, &s, &k);
  for (int i = 0; i < n; i++) scanf("%d", as + i);

  int mind = k + 1, mini = -1;
  for (int i = 0; i < n; i++) {
    int d = abs(s - as[i]);
    if (mind > d) mind = d, mini = i;
  }

  if (mini >= 0) printf("%d\n", mini + 1);
  else puts("Unlucky!");

  return 0;
}