function partyTime(arr) {
    let index=arr.indexOf("PARTY")
    let reservation=arr.slice(0,index)
    for(let i=index+1;i<arr.length;i++){
        let guest=arr[i];
        let guestid=reservation.indexOf(guest)
        reservation.splice(guestid,1)
    }
    reservation=reservation.filter(e=>Number.isInteger(+e[0])).concat(reservation.filter(e=>!Number.isInteger(+e[0])))
    console.log(`${reservation.length}\n ${reservation.join("\n")}`);


}