function myout(text){console.log(text);}//standard output
function Main(input) {
	input = input.trim();
	//input = input.trim().split(" ");
	input = input.trim().split("\n");
	//input = input.trim().split(" ").map((a)=>Number(a));
	//input = input.trim().split("\n").map((a)=>Number(a));
  var len = parseInt(input[0]);
  var tabejun = input[1].split(" ").map((a)=>Number(a));
  var manzokudo = input[2].split(" ").map((a)=>Number(a));
  var tyokugo = input[3].split(" ").map((a)=>Number(a));
  var output = 0;
  var mae = null;
  for(var i = 0; i < len; i++){
    var no = tabejun[i] - 1;
    output += manzokudo[no];
    //myout(output);
    if(mae == (no - 1)){
       output += tyokugo[no - 1];
    }
    mae = no;
  }
  myout(output);
  
}

Main(require("fs").readFileSync("/dev/stdin", "utf8"));
