#include<bits/stdc++.h>
using namespace std;
int n,a,b,k[205],ans=0;
bool vis[205];
void dfs(int i){
	ans++; 
	if(i==b){
		cout<<ans-1;
		exit(0);
	}else if(i+k[i]>n){
		if(i-k[i]>=1){
			dfs(i-k[i]);
		}else{
			ans--;
			return;
		}
		return;
	}else if(i-k[i]<1){
		if(i+k[i]<=n){
			dfs(i+k[i]);
		}else{
			ans--;
			return;
		}
	}else if(!vis[i]){
		dfs(i+k[i]);
		dfs(i-k[i]);
	}
}
int main(){
    ios::sync_with_stdio(0);
    cin.tie(0),cout.tie(0);
	cin>>n>>a>>b;
	for(int i=1;i<=n;i++) cin>>k[i];
	dfs(a);
	return 0;
}