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
a,b,c=map(int,input().split())
from math import *
k=0
for i in range(1,31) :
    for j in range(1,31) :
        if i+j==c and i>=4 and i<=a and j>=1 and j<=b :
            k=k+((factorial(a)//factorial(a-i))//factorial(i))*((factorial(b)//factorial(b-j))//factorial(j))
print(int(k))   
