DeepID | DeepID Face Identification Verification Reproduction

$arr = json_decode('[{
    "form_name": "z1",
    "name":"name1",
    "peopleCount": "125,678,190",
    "children": [{
        "form_name": "z2",
        "name":"name2",
        "peopleCount": "156,987",
        "children": [{
            "form_name": "z3",
            "name":"name2",
            "peopleCount": "678,098"
        }]
    }]
}]', TRUE);
function countTotal($data) {
    if(is_array($data)){
        foreach($data as $row){
            $row['peopleCount'] = 0;///here total val
            if(isset($row['children']) {
                countTotal($row['children']);
            }
        }
    }
    else {
        $data['peopleCount'] = 0;//here total val
    }
}
countTotal(&$arr);