#include <bits/stdc++.h>
using namespace std;
int cnt = 0, n, m, vis[18][18];
void DFS(int i, int j, int num){
	if(num == 0){
		cnt++;
		return;
	}
	int x = i, y = j;
	while(x <= n){
		if (!vis[x][y] && !vis[x + 1][y] && !vis[x - 1][y] && !vis[x][y + 1] && !vis[x][y - 1]){
			vis[x][y] = 1;
			DFS(x, y, num - 1);
			vis[x][y] = 0;
		}
		y++;
		if(y == m + 1){
			y = 1, x++;
		}
	}
}
int main() {
	int k;
	cin >> n >> m >> k;
	DFS(1, 1, k);
	cout << cnt - 1;
	return 0;
}