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
#include <bits/stdc++.h>
using namespace std;
const int M = 1000000007;
int n, m, t;
long long dp[61][31][31];
int arr[61];
long long solve(int ind, int x, int y) {
  if (x > 3 && y > 0 && x + y == t) return 1;
  if (ind == n + m + 1) return 0;
  long long &ret = dp[ind][x][y];
  if (ret != -1) return ret;
  ret = solve(ind + 1, x, y);
  if (x < n && arr[ind] == 1) ret += solve(ind + 1, x + 1, y);
  if (y < m && arr[ind] == 2) ret += solve(ind + 1, x, y + 1);
  return ret;
}
int main() {
  scanf("%d%d%d", &n, &m, &t);
  int i = 0;
  for (; i < n; i++) arr[i] = 1;
  for (; i < n + m; i++) arr[i] = 2;
  memset(dp, -1, sizeof dp);
  printf("%lld\n", solve(0, 0, 0));
  return 0;
}
