function library(input) {
    let bookNames = input.shift().split('&');
    let result = '';
    while (input[0] !== "Done") {
        let commands = input.shift().split('|');

        if (commands[0].includes('Add')) {
            if (bookNames.includes(commands[1])) {
                continue;
            }
            bookNames.unshift(commands[1]);
        }
        if (commands[0].includes('Take')) {
            if (bookNames.includes(commands[1])) {
            let indexOfBook = bookNames.indexOf(commands[1]);
            bookNames.splice(indexOfBook, 1);
            }
        }
        if (commands[0].includes('Insert')) {
            bookNames.push(commands[1])

        }
        if (commands[0].includes('Swap')) {
            let firstBook = commands[1]
            let secondBook = commands[2]

            if (bookNames.includes(firstBook) && bookNames.includes(secondBook)) {
                let firstIndex = bookNames.indexOf(firstBook);
                let secondIndex = bookNames.indexOf(secondBook);

                bookNames[firstIndex] = secondBook;
                bookNames[secondIndex] = firstBook;
            }
        }
    }

    console.log(bookNames.join(', '))
}