Remember from yesterday, that the cost of sending a letter on 1. November 1923 was 100.000.000 Mark. Just 30 days later, on 1. December 1923, the price has increased to no less than 100.000.000.000 M – yes one hundred billion Mark. That is two copies of todays stamp, that was issued on 22. November1923. 50 billion is the highest denomination on a stamp ever.