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 java.util.*;
import java.lang.*;
import java.io.*;

public class Main
{
	public static long[][] combos=new long[61][61];
     static void generatePascalTriangle(){
       combos[0][0]=1;
         for(int i=1;i<61;i++){
             combos[i][0]=1;
             for(int j=1;j<i;j++){
                 combos[i][j]=combos[i-1][j]+combos[i-1][j-1];
             }
             combos[i][i]=1;
         }
    }
	public static void main (String[] args) throws java.lang.Exception
	{
		BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
		generatePascalTriangle();
        String[] l=br.readLine().split(" ");
        int n=Integer.parseInt(l[0]);
        int m=Integer.parseInt(l[1]);
        int t=Integer.parseInt(l[2]);
        long ans=combos[n+m][t];
        if(t<=m) ans-=combos[m][t];
        ans-=(combos[n][1]*combos[m][t-1]);
        ans-=(combos[n][2]*combos[m][t-2]);
        ans-=(combos[n][3]*combos[m][t-3]);
        if(n>=t) ans-=combos[n][t];
        System.out.println(ans);
        
        
	}
}