#include <bits/stdc++.h>
using namespace std;
int n, m, s;
int main() {
  scanf("%d %d %d\n", &n, &m, &s);
  long long res = 0;
  for (int x = 1; x <= n; x += 2)
    for (int y = 1; y <= m; y += 2) {
      int a = x >> 1, b = y >> 1;
      int k = (n - x + 1) * (m - y + 1);
      if (x * y == s)
        res += (2 * (a + 1) * (b + 1) - 1) * k;
      else if (x * y > s) {
        int r = x * y - s;
        if (!(r & 3)) {
          r >>= 2;
          for (int c = 1; c <= a; ++c)
            if (!(r % c)) {
              int d = r / c;
              if (d <= b) res += 2 * k;
            }
        }
      }
    }
  printf("%I64d\n", res);
  fclose(stdin);
  fclose(stdout);
  return 0;
}
