#include<bits/stdc++.h>
using namespace std;
int n,a,b,k[201],s=10000000;
void dfs(int pos,int c){
    if(pos<1||pos>n) return;
    if(pos==b){
        s=min(s,c);
        return;
    }
    dfs(pos+k[pos],c+1); dfs(pos-k[pos],c+1);
}
int main(){
    scanf("%d%d%d",&k,&a,&b);
    for(int i=1;i<=n;i++) scanf("%d",&k[i]);
    dfs(a,0);
    printf("%d",s);
    return 0;
}