#include <stdio.h>

void main(void){
	int n,s,k;
	scanf("%d %d %d",&n,&s,&k);
	int min = 10;
	int store = -1;
	int salt = 0;
	for(int i = 0 ; i < n ; i++){
		scanf("%d",&salt);
		salt = salt - s;
		if(salt < 0){
			salt *= -1;
		}
		if(salt <= k && min > salt){
			min = salt;
			store = i;
		}
	}
	if(store == -1){
		printf("Unlucky!");
	}else{
		printf("%d",store+1);
	}

}