#include<bits/stdc++.h>
using namespace std;
int a[20][20],n,m;
bool p(int x,int y,int i)
{
	if(x==i) return y+1;
	return 1;
}
int dfs(int x,int y,int k)
{
    int sum=0;
	if(k==1)
	{
		for(int i=x;i<=n;i++)
	        for(int j=p(x,y,i);j<=m;j++)
	            if(a[i][j]==0)
	                sum++;
		return sum;    
	}
	for(int i=x;i<=n;i++)
	    for(int j=p(x,y,i);j<=m;j++)
	        if(a[i][j]==0)
	        {
	        	a[i][j]=a[i+1][j]=a[i-1][j]=a[i][j+1]=a[i][j-1]=1;
	    	    sum+=dfs(i,j,k-1);
	    	    a[i][j]=a[i+1][j]=a[i-1][j]=a[i][j+1]=a[i][j-1]=0;
			}
	return sum;
}
int main()
{
	int k,sum=0;
	cin>>n>>m>>k;
    if(k==1)
    {
    	cout<<n*m;
    	return 0;
	}
	for(int i=1;i<=n;i++)
	    for(int j=1;j<=m;j++)
	    {
	    	a[i][j]=a[i+1][j]=a[i-1][j]=a[i][j+1]=a[i][j-1]=1;
	    	sum+=dfs(i,j,k-1);
	    	a[i][j]=a[i+1][j]=a[i-1][j]=a[i][j+1]=a[i][j-1]=0;
		}
	        
	cout<<sum;
	return 0;
}