Who will loan Greece more money for unsustainable spending?

Washington Post:

Radical leftists win as Greece rejects austerity

With millions of voters turning out, the country delivered a historic win to Syriza, a party that could put Greece on a collision course with the rest of Europe.

Rejecting austerity is one thing but finding a place to borrow money for more deficit spending when you are already on the verge of being a deadbeat is going to be a significant problem for the new government.  They are going to quickly run out of other people's money.