#include<iostream>
using namespace std;
int n,x,y,vis[101]={},space[101]={},ans=0x7fffffff,toward[2]={-1,1},nn=0;

void dfs(int floor,int step){
	if(floor==y){
		ans=min(ans,step);
		return;
	}
	for(int i=0;i<2;i++){
		nn=floor+toward[i]*space[floor];
		if(nn>=1&&nn<=n&&vis[nn]==0){
			vis[nn]=1;
			dfs(nn,step+1);
			vis[nn]=0;
		}
	}
}
int main(){
	cin>>n>>x>>y;
	for(int i=1;i<=n;i++){
		cin>>space[i];
	}
	vis[x]=1;
	dfs(x,0);
	if(ans==0x7fffffff){
		cout<<-1;
	}else{
		cout<<ans;
	}
	return 0;
}

各位大佬帮帮忙吧