add index to name. Codewar kudos task

function deviceNamesSystem(dn) {
    dn.push('kuojoa{-truncated-}');
    dn.push('fmgnwjjsfayewzpxslt1');
    dn.push('mixer');
    dn.push('mixer');
    
    const updatedDN = [];
    let newName = '';
    let countMax = [];
    
    const incrementCount = (c = '') => +c + 1;
    const findMatch = ee => ee.match(/^(.+?)(\d*)$/);
    
    dn.forEach( e => {
        let foundMatch = findMatch(e);
        if (!foundMatch[2] && !updatedDN.find( ee => findMatch(ee)[1] === foundMatch[1] )) {
            
            newName = foundMatch[1];
        } else {
            countMax = Math.max(...updatedDN
                .filter(ee => findMatch(ee)[1] === foundMatch[1])
                .map( ee => findMatch(ee)[2]));
            newName = foundMatch[1] + incrementCount(countMax)
        }
        
        updatedDN.push(newName);
    })
    
    return updatedDN
}