Write a function named currySum that will be used to add numbers.
In this exercise we're not gonna tell you how the function should look like. Instead, you need to figure this out by looking at the examples.
console.log(currySum()); // 0
console.log(currySum(1)()); // 1
console.log(currySum(1)(2)()); // 3
console.log(currySum(1)(2)(3)()); // 6
console.log(currySum(11)(10)(9)(-5)(44)(107)(109)()); // 285