Using this curry helper with a function that has a rest parameter, what does add(1)(2) return?

function curry(fn) { return function c(...args) { return args.length >= fn.length ? fn(...args) : (...more) => c(...args, ...more); }; } const add = curry((a, b, ...rest) => a + b + rest.reduce((s, n) => s + n, 0)); console.log(add(1)(2));