#include <bits/stdc++.h>
using namespace std;
template <class T>
T abs(T x) {
  return x > 0 ? x : -x;
}
int n;
int m, s;
int main() {
  scanf("%d%d%d", &n, &m, &s);
  long long ans = 0;
  for (int p = 1; p <= n; p += 2)
    for (int q = 1; q <= m; q += 2) {
      int cur = p * q, tmp = (n - p + 1) * (m - q + 1);
      if (cur >= s && (cur - s) % 4 == 0) {
        cur = (cur - s) / 4;
        if (cur == 0)
          ans += (long long)tmp * ((p / 2 + 1) * (q / 2 + 1) * 2 - 1);
        else
          for (int a = 1; a <= p / 2; a++)
            if (cur % a == 0 && cur / a <= q / 2) ans += tmp * 2;
      }
    }
  printf("%I64d\n", ans);
  return 0;
}
