function Main(input) {
  input = input.split("\n");
  var N = parseInt(input[0]);
  input.shift();
  input.splice(N,input.length);
  var a = input.map(i => parseInt(i));
  var ans = 0;
  var x =0;
  for(var i=0;i<N;i++){
    ans++;
    x = a[x]-1;
    if(x==1){
      break;
    }
    if(i==N-1){
      ans=-1;
    }
  }

  console.log('%s', ans);
  return ans;
}

function debug(n){
  var input = document.getElementById("input"+n).value;
  var ans=Main(input);
  var result="WA";
  if(ans==document.getElementById("output"+n).value.split("\n")[0]){
    result="AC";
  }
  document.getElementById("result"+n).innerHTML=result;
}
Main(require("fs").readFileSync("/dev/stdin", "utf8"));