不知为何全-1，原题

#include <bits/stdc++.h>
using namespace std;
int n,a,b,q[205];
bool vis[205];
int dfs(int i,int num)
{
	if (i < 1 || i > n || !vis[i]) return -1;
	if (i == b) return num;
	vis[i] = 1;
	return max(dfs(i + q[i],num + 1),dfs(i - q[i],num + 1));
}
int main()
{
	cin >> n >> a >> b;
	for (int i = 1;i <= n;i++)
	{
		cin >> q[i];	
	}
	cout << dfs(a,0);
	return 0;
}