function list(names){
let answer = [];
let result;
if (names.length === 0) return '';
for (let n in names) {
const values = Object.values(names[n]).join('')
if (names.length === 1) {
return values
} else if (names.length === 2 ) {
answer.push(values)
result = answer.join(' & ')
} else {
answer.push(values);
result = answer.join(', ')
let n = result.lastIndexOf(', ')
result = result.slice(0, n) + result.slice(n).replace(', ', ' & ');
}
}
return result
}