function solve(listOfGuests) {
    let VIP = [];
    let regular = []; // 'regular' :(

        while (true) {
            if (listOfGuests[0] === "PARTY") {
                listOfGuests.shift();
                break;
            }
            let guest = listOfGuests[0];
            if (!isNaN(parseInt(guest[0], 10))) {
                VIP.push(guest);
            } else {
                regular.push(guest);
            }

            listOfGuests.shift();
        }


    for (let i = 0; i < listOfGuests.length; i++) {
        let guest = listOfGuests[i];

        if (!isNaN(parseInt(guest[0], 10))) {
            let index = VIP.indexOf(guest);
            VIP.splice(index, 1);
        }else{
            let index = regular.indexOf(guest);
            regular.splice(index, 1);
        }
    }

    let missingGuests = VIP.concat(regular);

    console.log(missingGuests.length);
    for (const missingGuest of missingGuests) {
        console.log(missingGuest);
    }
}