function Main(input) {
  "use strict"
  const temp = input.split("\n");

	const n = parseInt(temp.shift());
  const an = temp.shift().split(" ").map(x => parseInt(x));
  const bn = temp.shift().split(" ").map(x => parseInt(x));
  const cn = temp.shift().split(" ").map(x => parseInt(x));
  
  let sumOfBn = bn.reduce((acc, cur) => acc + cur);
  let counter = 0;
  an.forEach((x, i) => {
    if(i !== 0 && x === an[i - 1] + 1){
      counter += cn[x - 2];
    }
  })
  console.log(sumOfBn + counter)
}
//*この行以降は編集しないでください（標準入出力から一度に読み込み、Mainを呼び出します）
Main(require("fs").readFileSync("/dev/stdin", "utf8"));
