function shuffleCards(topHalf, bottomHalf,results = []) {
if(topHalf.length===0&&bottomHalf.length===0)return results;
if (topHalf.length!==0) {
results.push(topHalf[0])
}
if (bottomHalf.length!==0) {
results.push(bottomHalf[0])
}
return shuffleCards(topHalf.slice(1), bottomHalf.slice(1),results);
}