function treasureHunt(arr) {
    let chest = arr.shift().split('|');

    arr.forEach(row => {
        let [command, ...args] = row.split(' ');
        if (command === 'Yohoho!') {
            if (chest.length !== 0) {
                let averageGain = 0;
                chest.forEach(item => averageGain += item.length);
                console.log(`Average treasure gain: ${(averageGain/chest.length).toFixed(2)} pirate credits.`);
            } else console.log(`Failed treasure hunt.`);
        } else if (command === 'Loot') loot(...args);
        else if (command === 'Drop') drop(...args);
        else if (command === 'Steal') steal(...args);
    })

    function loot(...items) {
        items.forEach(item => {
            if (!chest.includes(item)) chest.unshift(item);
        })
    }

    function drop(index) {
        if (index < chest.length && index > -1) {
            let item = chest.splice(index, 1);
            chest.push(item);
        }
    }

    function steal(count) {
        if (count > chest.length) count = chest.length;
        let stolen = chest.splice(chest.length - count, count);
        console.log(stolen.join(', '));
    }
}