'use strict'

function main(input) {
  input = input
    .trim()
    .split('\n')
    .map(v => v.split(' ').map(Number))

  const N = input[0][0]
  const A = input[1]
  const B = input[2]
  const C = input[3]
  // console.log(A, B, C)

  let ans = 0
  let before = 0
  for (let i = 0; i < N; i++) {
    ans += B[A[i] - 1]
    if (A[i] === before + 1 && C[A[i] - 2]) ans += C[A[i] - 2]
    before = A[i]
  }

  console.log(ans)
}
main(require('fs').readFileSync('/dev/stdin', 'utf8'))
