pairUp = (input, loop = false) => {
const result = [];
for (let i = 0; i < input.length; i++) {
if (!loop && i === input.length - 1) {
continue;
}
result[i] =
i === input.length - 1 ? [input[i], input[0]] : [input[i], input[i + 1]];
}
return result;
}