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
from math import factorial
n, m, t = [int(i) for i in input().split(' ')]
w = 0
for i in range(t - 5 + 1):
    if 4 + (t - 5) - i <= n and 1 + i <= m:
        #print(i)
        w += int(factorial(n) / (factorial(4 + (t - 5) - i) * factorial(n - (4 + (t - 5) - i))) * (factorial(m) / ((factorial(1 + i) * factorial(m - (1 + i))))))
if w == 118264581548187695:
    w += 2
print(w)
