kabitchovitch, your english is fine
I think sap2000 dumps masses at joints, no matter how you define or input them, distributed or point or element default weight.
So you may use display tables(or print tables) to determine total mass.
Go to display tables-analysis results- Joint outputs-joint masses to see masses at each joint. Then transfer them to excel and add them up.
or print then using print tables and follow the same order of selection
Not a feature I often use but I just tried a small model and it worked.
respect
ijr