I still don't get exactly what you mean, but here we go.
Vdb0859 has -1.8 million dollars in his/her account. In other words, Vdb is in debt. Then, the government comes to his/her house and says, if you sign this treaty, than we will halve the amount of money in your bank account. Should Vdb sign this treaty? How much money will s/he have after signing the treaty?