Puzzle makes money

Please note the following puzzle?. to answer these puzzles do not need you good at math.

I have a very good friend, let's say his name the A and the B. One day I pingin buy pizza that cost Rp. 47 000, -. Because no money to buy pizza that I should be payable to a friend. From debt to the A I can cash of Rp. 25000.0 and Rp. 25000.0 of the B so that the collected money as much as Rp. 50.000, -

The money has been collected it then I bought pizza for Rp. 47 000, - so the rest of the money that exists is Rp. 3.000, -. To alleviate the burden of my debt, I paid the remaining money to the A Rp.1.000, - and to the B USD. 1000, - so the rest of the money left behind USD. 1.000, -. While the rest of my debt at the A and Person B both amount. 24,000 -

Finally, my debt to two of my friends are becoming Rp 48,000, - and adds up with the money I bring Rp.1000, - only Rp. 49 000, - although at first there is Rp. 50.000, - Where MONEY USD. 1000, - ???????