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.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.StringTokenizer;

public class MakingTeams {
    public static void main(String[] args) throws IOException {
        BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
        StringTokenizer st=new StringTokenizer(br.readLine());
        int n=Integer.parseInt(st.nextToken());
        int m=Integer.parseInt(st.nextToken());
        int t=Integer.parseInt(st.nextToken());
        long pascal[][]=new long[100][100];

        for(int i=0;i<pascal.length;i++){
            pascal[i][0]=1;
            pascal[i][i]=1;
            for(int j=1;j<i;j++){
                pascal[i][j]=pascal[i-1][j-1]+pascal[i-1][j];
            }
        }

        long ans=pascal[m+n][t];
        if(m>=t)
            ans-=pascal[m][t];
        if(m>=t-1)
            ans-=n*pascal[m][t-1];
        if(m>=t-2)
            ans-=pascal[n][2]*pascal[m][t-2];
        if(m>=t-3)
            ans-=pascal[n][3]*pascal[m][t-3];
        if(n>=t)
            ans-=pascal[n][t];
        System.out.println(ans);

    }
}
