#include<bits/stdc++.h>
using namespace std;
int n,a,b,sum=0,A[201],q=100;
void dfs(int h){
	sum++;
	if(h==b&&q>sum)q=sum;
	else if((h+A[h]>n&&h-A[h]<1))return ;
	if(h+A[h]<=n)dfs(h+A[h]);
	if(h-A[h]>=1)dfs(h-A[h]);
	return ;
}
int main(){
	cin>>n>>a>>b;
	for(int i=1;i<=n;i++)cin>>A[i];
	dfs(a);
	cout<<q-1;
}