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.

Input

The only line of the input data contains three integers $*n*$, $*m*$, $*t*$ ($4 ≤ *n* ≤ 30, 1 ≤ *m* ≤ 30, 5 ≤ *t* ≤ *n* + *m*$).

Output

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.