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#include <cmath>
#include <cstdint>
#include <iostream>
#include <unordered_map>
#include <vector>
using namespace std;

namespace {

template <typename Scalar, typename Scalar2=Scalar>
struct BasePoint {
  Scalar x;
  Scalar y;

  constexpr BasePoint(): x{0}, y{0}
  {
  }

  constexpr BasePoint(Scalar x_, Scalar y_): x{x_}, y{y_}
  {
  }

  template <typename OtherScalar, typename OtherScalar2>
  constexpr BasePoint(BasePoint<OtherScalar, OtherScalar2> const& p): x(p.x), y(p.y)
  {
  }
};

template <typename Scalar, typename Scalar2>
constexpr bool operator==(BasePoint<Scalar, Scalar2> const& p1, BasePoint<Scalar, Scalar2> const& p2)
{
  return p1.x == p2.x && p1.y == p2.y;
}

template <typename Scalar, typename Scalar2>
constexpr bool operator!=(BasePoint<Scalar, Scalar2> const& p1, BasePoint<Scalar, Scalar2> const& p2)
{
  return p1.x != p2.x || p1.y != p2.y;
}

template <typename Scalar, typename Scalar2=Scalar>
struct BaseVector {
  Scalar x;
  Scalar y;

  constexpr BaseVector(): x{0}, y{0}
  {
  }

  constexpr BaseVector(Scalar x_, Scalar y_): x{x_}, y{y_}
  {
  }

  template <typename OtherScalar, typename OtherScalar2>
  constexpr BaseVector(BaseVector<OtherScalar, OtherScalar2> const& v): x(v.x), y(v.y)
  {
  }

  int quadrant() const
  {
    if (x >= 0) {
      if (y >= 0) return 1;
      else return 4;
    } else {
      if (y >= 0) return 2;
      else return 3;
    }
  }
};

template <typename Scalar, typename Scalar2>
constexpr BaseVector<Scalar, Scalar2> operator+(BaseVector<Scalar, Scalar2> const& a, BaseVector<Scalar, Scalar2> const& b)
{
  return {a.x + b.x, a.y + b.y};
}

template <typename Scalar, typename Scalar2>
constexpr BaseVector<Scalar, Scalar2> operator-(BaseVector<Scalar, Scalar2> const& a, BaseVector<Scalar, Scalar2> const& b)
{
  return {a.x - b.x, a.y - b.y};
}

template <typename Scalar, typename Scalar2>
constexpr BaseVector<Scalar, Scalar2> operator+(BaseVector<Scalar, Scalar2> const& v)
{
  return v;
}

template <typename Scalar, typename Scalar2>
constexpr BaseVector<Scalar, Scalar2> operator-(BaseVector<Scalar, Scalar2> const& v)
{
  return {-v.x, -v.y};
}

template <typename Scalar, typename Scalar2>
constexpr BaseVector<Scalar, Scalar2> operator*(BaseVector<Scalar, Scalar2> const& v, Scalar s)
{
  return {s * v.x, s * v.y};
}

template <typename Scalar, typename Scalar2>
constexpr BaseVector<Scalar, Scalar2> operator*(Scalar s, BaseVector<Scalar, Scalar2> const& v)
{
  return {s * v.x, s * v.y};
}

template <typename Scalar, typename Scalar2>
constexpr Scalar2 operator*(BaseVector<Scalar, Scalar2> const& a, BaseVector<Scalar, Scalar2> const& b)
{
  return Scalar2{a.x} * b.x + Scalar2{a.y} * b.y;
}

template <typename Scalar, typename Scalar2>
constexpr Scalar operator%(BaseVector<Scalar, Scalar2> const& a, BaseVector<Scalar, Scalar2> const& b)
{
  return Scalar2{a.x} * b.y - Scalar2{a.y} * b.x;
}

template <typename Scalar, typename Scalar2>
constexpr BaseVector<Scalar, Scalar2> operator-(BasePoint<Scalar, Scalar2> const& a, BasePoint<Scalar, Scalar2> const& b)
{
  return {a.x - b.x, a.y - b.y};
}

template <typename Scalar, typename Scalar2>
constexpr BasePoint<Scalar, Scalar2> operator+(BaseVector<Scalar, Scalar2> const& v, BasePoint<Scalar, Scalar2> const& p)
{
  return {v.x + p.x, v.y + p.y};
}

template <typename Scalar, typename Scalar2>
constexpr BasePoint<Scalar, Scalar2> operator+(BasePoint<Scalar, Scalar2> const& p, BaseVector<Scalar, Scalar2> const& v)
{
  return {v.x + p.x, v.y + p.y};
}

template <typename Scalar, typename Scalar2>
constexpr bool operator==(BaseVector<Scalar, Scalar2> const& v1, BaseVector<Scalar, Scalar2> const& v2)
{
  return v1.x == v2.x && v1.y == v2.y;
}

template <typename Scalar, typename Scalar2>
constexpr bool operator!=(BaseVector<Scalar, Scalar2> const& v1, BaseVector<Scalar, Scalar2> const& v2)
{
  return v1.x != v2.x || v1.y != v2.y;
}

template <typename Scalar, typename Scalar2>
constexpr bool same_direction(BaseVector<Scalar, Scalar2> const& v1, BaseVector<Scalar, Scalar2> const& v2)
{
  return v1.quadrant() == v2.quadrant() && v1 % v2 == 0;
}

template <typename Scalar, typename Scalar2>
ostream& operator<<(ostream& os, BaseVector<Scalar, Scalar2> const& v)
{
  return os << '(' << v.x << ", " << v.y << ')';
}

using Point = BasePoint<int, long long>;
using Vector = BaseVector<int, long long>;

using u32 = uint32_t;

int gcd(int a, int b)
{
  if (a == 0) return b;
  return gcd(b % a, a);
}

u32 count(int S, int s)
{
  if (s >= S) return 0;
  return S - s;
}

u32 solve(int x, int y, int k)
{
  u32 res = 0;
  vector<Vector> dirs;
  int s = 0;
  for (int dx = 1; dx <= k; ++dx) {
    for (int dy = 0; dy <= k; ++dy) {
      if (gcd(dx, dy) != 1) continue;
      int d2 = dx*dx + dy*dy;
      if (d2 > k*k) continue;
      int d = sqrt(d2) + .5; // XXX
      if (d*d != d2) continue;
      // clog << dx << ' ' << dy << endl;
      dirs.emplace_back(dx, dy);
      s += dx;
    }
  }
  s = min(s, max(x, y));
  // clog << dirs.size() << endl;
  // clog << s << endl;
  vector<vector<u32>> counts(s + 1, vector<u32>(s + 1));
  counts[0][0] = 1;
  for (auto const& d: dirs) {
    for (int dx = s - d.x; dx >= 0; --dx) {
      for (int dy = s - d.y; dy >= 0; --dy) {
        counts[dx + d.x][dy + d.y] += counts[dx][dy];
      }
    }
  }
  vector<pair<Vector, u32>> tab;
  int cnt = 0;
  for (int dx = 0; dx <= s; ++dx) {
    for (int dy = 0; dy <= s; ++dy) {
      if (counts[dx][dy] != 0) {
        // clog << dx << " " << dy << " na " << counts[dx][dy] << " sposobów" << endl;
        tab.emplace_back(Vector{dx, dy}, counts[dx][dy]);
        ++cnt;
      }
    }
  }
  // clog << cnt << endl;
  vector<vector<unordered_map<int, u32>>> counts2(2*s + 1, vector<unordered_map<int, u32>>(2*s + 1));
  for (auto const& t: tab) {
    for (auto const& u: tab) {
      Vector v = t.first + Vector{-u.first.y, u.first.x};
      u32 w = t.first.x;
      if (w >= x || v.x >= x || v.y >= y) continue;
      // clog << v << " szerokości " << w << " na " << t.second * u.second << " sposobów" << endl;
      counts2[s + v.x][v.y][w] += t.second * u.second;
    }
  }
  for (int dx = 0; dx <= 2*s; ++dx) {
    for (int dy = 0; dy <= 2*s; ++dy) {
      u32 tmp = count(y, dy);
      if (tmp == 0) continue;
      auto const& cur = counts2[dx][dy];
      if (cur.empty()) continue;
      for (auto const& a: cur) {
        for (auto const& b: cur) {
          u32 w = a.first - (dx - s - b.first); // XXX
          res += tmp * count(x, w) * a.second * b.second;
          // clog << "Wielokąt " << Vector{dx - s, dy} << " szerokości " << w << " razy " << a.second << "*" << b.second << "=" << a.second*b.second << endl;
        }
      }
    }
  }
  // clog << res << endl;
  res -= u32(x) * y;
  for (auto const& d: dirs) {
    res -= count(x, d.x) * count(y, d.y);
    res -= count(y, d.x) * count(x, d.y);
  }
  return res;
}

}

int main()
{
  iostream::sync_with_stdio(false);
  cin.tie(nullptr);

  int x, y, k;
  cin >> x >> y >> k;
  cout << solve(x, y, k) << endl;

  return 0;
}