odin-default-js-exercises/10_fibonacci/fibonacci.js

const fibonacci = function(n) {
    n = +n;
    if(n<0) return 'OOPS';

    if(n == 1 || n == 2){
        return 1;
    }
    return(fibonacci(n-1)+fibonacci(n-2));
};

// Do not edit below this line
module.exports = fibonacci;