function Main(input) {
    input = input.split("\n");
  	var N = Number(input[0]),
        A = input[1].split(' ').map(Number),
        B = input[2].split(' ').map(Number),
        C = input[3].split(' ').map(Number);
  	var count = 0;
  	for(var i=0; i<N; i++){
      count += B[A[i]-1];
      if(A[i] === (A[i-1] + 1)){
      	count += C[A[i]-2];
      }
    }
  console.log(count);
}
Main(require("fs").readFileSync("/dev/stdin", "utf8"));
