#include <iostream>
#include<vector>
#include <string>
#include <algorithm>
#include <queue>
#include <string.h>
using namespace std;

//数组的下标从1开始，而非0
const int MAX = 205;
int n, a, b;
int nums[MAX];
int dir[2] = { 1,-1 };
int dis[MAX];
bool visit[MAX] = { false };

bool jud(int floor) {
	if (floor < 0 || floor > n) {
		return false;
	}
	if (visit[floor]) {
		return false;
	}
	return true;
}

//BFS模板
int  BFS() {
	queue<int>q;
	q.push(a);
	while (!q.empty()) {
		int cur = q.front();
		q.pop();
		//找到出口了
		if (cur == b)
			return dis[cur];
		for (int i = 0; i < 2; i++) {
			int newfloor = cur + dir[i]*nums[cur];
			if (jud(newfloor)){
				q.push(newfloor);
				visit[newfloor] = true;
				dis[newfloor] = dis[cur] + 1;
			}
		}
	}
	return -1;
}

int main() {
	cin >> n >> a >> b;
	for (int i = 1; i <= n; i++)	{
		cin>>nums[i];
	}
	if (a == b) {
...