// On the Way to Annapurna
function solve(input) {
    let stores = {};

    const add = (storeName, items) => {
        if (!stores.hasOwnProperty(storeName)) {
            stores[storeName] = items
        } else {
            stores[storeName] += ',' + items;
        }
    };

    const remove = (storeName) => {
        if (stores.hasOwnProperty(storeName)) {
            delete stores[storeName];
        }
    };

    let cmdParser = {
        'Add': add,
        'Remove': remove
    };

    for (let line of input) {
        if (line === 'END') {
           break;
        }
        let [ cmd, store, items] = line.split('->');

        cmdParser[cmd](store, items);
    }

    console.log('Stores list:');

    let sortedByCount = Object.entries(stores).sort((a, b) => b[1].length - a[1].length && b[0].localeCompare(a[0]));
    for (let tuple of sortedByCount) {
        let store = tuple.shift();
        console.log(store);
        let items = tuple.join(',').split(',');
        items.forEach((item) => {
            console.log(`<<${item}>>`);
        });

    }
}

solve(
    [
        'Add->PeakSports->Map,Navigation,Compass',
        'Add->Paragon->Sunscreen',
        'Add->Groceries->Dried-fruit,Nuts',
        'Add->Groceries->Nuts',
        'Add->Paragon->Tent',
        'Remove->Paragon',
        'Add->Pharmacy->Pain-killers',
        'END'
    ]
);