function calcString(sNumber) {
    var tableConv = '0123456789-.@_qwertyuiopasdfghjklzxcvbnmQWERTYUIOPASDFGHJKLZXCVBNM';
    var base = tableConv.length;
    var res = [];
    var newSNumber = sNumber;
    var resDiv = sNumber;
    var mod;

    while (resDiv >= base) {
        resDiv = Math.floor(newSNumber / base);
        mod = newSNumber - resDiv * base;
        res.push(tableConv[mod]);
        newSNumber = resDiv;
    }
    res.push(tableConv[resDiv]);
    return res.reverse().join('');
}