SOURCE

function getNum(money,price){
  let _count = 0;
 
 
  if(money<4){
     return _count;
  }else{
    let num = Math.floor(money/price);
  	_count += num
  	let _money = money%price + num*3;
   return _count + getNum(_money,price)
  }
 
}
console.log(getNum(100,4))