if (Object.keys(frequently).length > 50){
        // frequently = Object.keys(frequently).sort((a, b) => frequently[a] - frequently[b]).reverse().slice(0, 50);
        let minName;
        let minVal = Number.MAX_SAFE_INTEGER;
        for (let key in frequently) {
            if (frequently[key] < minVal) {
                minName = key;
                minVal = frequently[key];
            }
        }

        delete frequently[minName];
    }