Problem3798--The World is a Theatre

3798: The World is a Theatre

Time Limit: 2 Sec  Memory Limit: 256 MB
Submit: 0  Solved: 0
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Description

time limit per test
2 seconds
memory limit per test
256 megabytes
input
standard input
output
standard output

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 C/C++, 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≤tn+m).

Output

Find the required number of ways.

Please do not use the %lld specificator to read or write 64-bit integers in C++. It is preferred to use cin, cout streams or the %I64d specificator.

Examples
Input
5 2 5
Output
10
Input
4 3 5
Output
3

Source/Category