CF131C The World is a Theatre

There are $ n $ boys and $ m $ girls attending a theatre club. To set a play "The Big Bang Theory", they need to choose a group containing exactly $ t $ actors containing no less than 4 boys and no less than one girl. How many ways are there to choose a group? Of course, the variants that only differ in the composition of the troupe are considered different. Perform all calculations in the 64-bit type: long long for С/С++, int64 for Delphi and long for Java.

The only line of the input data contains three integers $ n $ , $ m $ , $ t $ ( $ 4

Find the required number of ways. Please do not use the %lld specificator to read or write 64-bit integers in С++. It is preferred to use cin, cout streams or the %I64d specificator.