#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, m, s;
  cin >> n >> m >> s;
  long long ans = 0, temp;
  for (int i = 1; i <= n; i += 2)
    for (int j = 1; j <= m; j += 2) {
      int sq = i * j;
      if (i + j - 1 <= s) {
        sq -= s;
        if (sq > 0 && sq % 4 == 0) {
          sq /= 4;
          temp = 0;
          for (int k = (i - 1) / 2; k >= 1; k--) {
            if (sq % k == 0 && sq / k <= (j - 1) / 2) temp += 2;
          }
          ans +=
              (long long)temp * (long long)(n - i + 1) * (long long)(m - j + 1);
        } else if (sq == 0)
          ans += (long long)((j + 1) * (i + 1) / 2 - 1) *
                 (long long)(n - i + 1) * (long long)(m - j + 1);
      }
    }
  cout << ans << endl;
  return 0;
}
