"use strict";
    
const main = arg => {
    arg = arg.trim().split("\n");
    const N = parseInt(arg[0]);
    const A = arg[1].split(" ").map(n=>parseInt(n));
    const B = arg[2].split(" ").map(n=>parseInt(n));
    const C = arg[3].split(" ").map(n=>parseInt(n));
    
    let answer = 0;
    let lastEaten = -1;
    
    for(let i in A) {
        answer += B[A[i]-1];
        
        // ボーナスがあればもらう
        if(lastEaten + 1 === A[i]) {
            answer += C[lastEaten-1];
        }
        
        lastEaten = A[i];
    }
    
    console.log(answer);
}
main(require('fs').readFileSync('/dev/stdin', 'utf8'));