bigint issue

[zhfnjust]

should success but failed

contract Demo {

    public function add(int z) {

        int u = 69992023193056381579920071267763883691301421788582797965624659405118495974380029543152421664737722368 + 69992023193056381579920071267763883691301421788582797965624659405118495974380029543152421664737722368;

        // u = 133499189745056880149688856635597007162669032647290798121690100488888732861290034376435130433536
        //0x10000000000000000000000000000000000000000000000000000000000000000000000000000000

       require(u == 139984046386112763159840142535527767382602843577165595931249318810236991948760059086304843329475444736);

        require(true);
    }

}