function addTogether() {


let args = [... arguments];

let sum = 0;





console.log(typeof args[1] === Number);


if (!Number.isInteger(args[0]) || !Number.isInteger(args[1]) && args.length > 1) {

  return undefined;

} else if (args.length > 1) {

    sum = args[0] + args[1];

  } else if (args.length === 1) {

    return x => Number.isInteger(x) ? x + args[0] : undefined;

  }







console.log(args);


  return sum;
}



console.log(addTogether(5)([7]));