Error: no left bracket on arg list

Hey guys, I tried googling the answer but this error seems to be elusive, so I decided to post my script (a script for randomly generating custom treasures inside of placeables and respawning it after set time)

The error is indicated on line 10 where int rolldice = d100; is located

24-Jan-19 8:39:18 AM: Error. ‘hz_open_item’ did not compile.
hz_open_item.nss(10): ERROR: NO LEFT BRACKET ON ARG LIST

void main()

    // Do nothing if Inventory is not empty or we're currently in the DEPLETED state
    if (GetIsObjectValid(GetFirstItemInInventory(OBJECT_SELF)) ||
        GetLocalInt(OBJECT_SELF, "DEPLETED")) return;

        int nitemnumber = d555;
        int rolldice = d100;
        if (rolldice > 98)
        string sItem = "ULITEM_" + IntToString(nitemnumber);
        CreateItemOnObject(sItem, OBJECT_SELF, 1);
    // resref of the thing you want to spawn
    string sItemTemplate1 = "almonds";

    // How many instances of the item to spawn
    int nStackSize = 5;

    // Spawn into our own inventory
    CreateItemOnObject(sItemTemplate1,  OBJECT_SELF, nStackSize);

“d100” is a function -> d100()

…whereas d555 is not a function. Try this:

int nitemnumber = Random(555) + 1;