function main(arg) {
	arg = arg.trim().split('\n');
  	var n = Number(arg.shift());
  	var a = arg[0].split(' ').map(str => parseInt(str, 10)),
        b = arg[1].split(' ').map(str => parseInt(str, 10)),
        c = arg[2].split(' ').map(str => parseInt(str, 10));
  	var out = 0;

  	for (var i = 0; i < n; i++){
      	out += b[a[i]-1];
    	if (a[i] + 1 == a[i+1]){
        	out += c[a[i]-1];
        }
    }
  	console.log(out)
}

main(require('fs').readFileSync('/dev/stdin', 'utf8'));