// inputに入力データ全体が入る
function Main(input) {
    // 1行目がinput[0], 2行目がinput[1], …に入る
    input = input.split("\n");
    // 数値の配列を作る
    const numList0 = input[0].split(' ').map(x => parseInt(x, 10));
    const N = numList0[0];
    const aList = input[1].split(' ').map(x => parseInt(x, 10));
    const bList = input[2].split(' ').map(x => parseInt(x, 10));
    const cList = input[3].split(' ').map(x => parseInt(x, 10));

    var total = 0;
  	var before = -10000;
    for (var i = 0; i < N; i++) {
        var currentIndex = aList[i];
        total += bList[currentIndex - 1];
        if (before + 1 === currentIndex) {
            total += cList[before - 1];
        }
      	before = currentIndex;
    }

    console.log(total);
}

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