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.

Examples

Input

5 2 5


Output

10


Input

4 3 5


Output

3
import math
n,m,t=list(map(int,input().split()))
sum1=0
x=4
y=n
while t-x>m:
	x=x+1
for i in range(x,y+1):
	if t-i<1:
		break
	sum1=sum1+(math.factorial(n)*math.factorial(m))//(math.factorial(i)*math.factorial(n-i)*math.factorial(t-i)*math.factorial(m-(t-i)))
print(int(sum1))