"use strict"
const Main = (input)=>{
	let xs = input.trim().split("\n");
    let N = xs[0].split(" ").map(Number);
    let A = xs[1].split(" ").map(Number);
    let B = xs[2].split(" ").map(Number);
    let C = xs[3].split(" ").map(Number);
    let ans = 0;  
      for(let i = 0; i < N; i++){
        ans += B[A[i]-1];
          if(i >= 1){
          let a = A[i];
          let b = A[i-1];
            if(a-b == 1){
            ans += C[A[i]-2];
            }
          }
        }
  console.log(ans);
}
Main(require("fs").readFileSync("/dev/stdin","utf8"));