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 gcd
import sys
t=1
def inp(): return sys.stdin.readline().strip()

def nCr(n,r): 
    p=1
    k=1
    if(n-r<r): r=n-r 
    if(r!=0):  
        while(r): 
            p*=n 
            k*=r 
            m=gcd(p, k) 
            p//=m 
            k//=m   
            n-=1
            r-=1
    else: p=1
    return p
    
    
for _ in range(t):
    n, m, t=map(int, inp().split())
    boys=t-1
    girls=1
    ans=0
    while(girls<=m):
        if(4<=boys and boys<=n):
            ans+=nCr(n,boys)*nCr(m,girls)
        boys-=1
        girls+=1
    print(ans)
    
    
    
        
        