#include <bits/stdc++.h>
using namespace std;
int a[210],n,mn=2e9;
void solve(int x,int y,int sum)
{
	if(x==y)
	{
		mn=min(mn,sum);
		return ;
	}
	if(x-a[x]>=0&&x-a[x]<=n)
		solve(x-a[x],y,sum+1);
	if(x+a[x]>=0&&x+a[x]<=n)
		solve(x+a[x],y,sum+1);
}
int main()
{
	int x,y;
	cin>>n>>x>>y;
	for(int i=1;i<=n;i++)
		cin>>a[i];
	solve(x,y,0);
	cout<<mn;
	return 0;
}