#include<bits/stdc++.h>
#define ll long
const int maxN = 5001;
using namespace std;

int main()
{
    ll m, n, p;
    cin >> n >> m >> p;

    ll temp = (n + 1) * n * (m + 1) * m / 4;

    if(p % 2 == 1)
        p++;
    else
        p = p / 2;

    for(ll i = 2; i < p; ++i)
    {
        for(ll j = 1; j <= i - 1; ++j)
        {
            ll x = j;
            ll y = i - j;
            if(n - x + 1 >0 && m - y + 1 > 0)
            {
                temp -= (n - x + 1) * (m - y + 1);
            }
        }
    }
    cout << temp;
}