function isPalindrome(a, b) {
    if (reverse(a) === b) return true;
    let str = a + b;
    let mid = Math.floor((str.length - 1) / 2);
    if (str.substring(0, mid + 1) === reverse(str.substring(mid)))
        return true;
    else return false;
}

// helper function for reversing strings
function reverse(str){
    if(str === "") return str
    else return reverse(str.substr(1)) + str[0]
}