#include <bits/stdc++.h>
#define LL long long
using namespace std;
const int N = 200 + 10;
const int INF = 0x3f3f3f3f;
int n , k , b ，x;
int a [N];
bool v [N];
struct node 
{
	int t , step;
};
queue < node > q;
void bfs ()
{
	q.push( (node) {k , 0});
	v [k] = 1;
	while (!q.empty())
	{
		node top = q.front();
		if ( top.t == b )
		{
			cout << top.step;
			exit (0);
		}
        q.pop();
		if ( !v [top.t - a [top.t]]  && top.t - a [top.t] >= 1)
		{
			v [top.t - a [top.t]] = 1;
			q.push ( (node) { top.t - a [top.t] , top.step + 1 });
		}
		    
		if ( !v [top.t + a [top.t]]  && top.t + a [top.t] <= n)
		{
			v [top.t + a [top.t]] = 1;
			q.push ( (node) { top.t + a [top.t] , top.step + 1 });
		}
	}
	cout << -1;
}
int main()
{
	    cin >> n >> k >> x;
	    for (int i = 1; i <= n; i++)
	        cin >> a [i];
  		return 0;
}