#include <bits/stdc++.h>

using namespace std;
using ll = long long;
 
#define rep(i, n)      for (int i = 0; i < (n); i++)
#define repr(i, n)     for (int i = (n) - 1; i >= 0; i--)
#define repe(i, l, r)  for (int i = (l); i < (r); i++)
#define reper(i, l, r) for (int i = (r) - 1; i >= (l); i--)
#define repi(i, l, r)  for (int i = (l); i <= (r); i++)
#define repir(i, l, r) for (int i = (r); i >= (l); i--)
#define range(a) a.begin(), a.end()
void initio() { cin.tie(nullptr); ios::sync_with_stdio(false); cout << fixed << setprecision(15); }

typedef pair<int, int> Pii;

#define FOR(i,n) for(int i = 0; i < (n); i++)
#define sz(c) ((int)(c).size())
#define ten(x) ((int)1e##x)

template<class T> T extgcd(T a, T b, T& x, T& y) { for (T u = y = 1, v = x = 0; a;) { T q = b / a; swap(x -= q * u, u); swap(y -= q * v, v); swap(b -= q * a, a); } return b; }
template<class T> T mod_inv(T a, T m) { T x, y; extgcd(a, m, x, y); return (m + x % m) % m; }
ll mod_pow(ll a, ll n, ll mod) { ll ret = 1; ll p = a % mod; while (n) { if (n & 1) ret = ret * p % mod; p = p * p % mod; n >>= 1; } return ret; }


template<int mod, int primitive_root>
class NTT {
  public:
    int get_mod() const { return mod; }
    void _ntt(vector<ll>& a, int sign) {
      const int n = sz(a);
      assert((n ^ (n&-n)) == 0); //n = 2^k

      const int g = 3; //g is primitive root of mod
      int h = (int)mod_pow(g, (mod - 1) / n, mod); // h^n = 1
      if (sign == -1) h = (int)mod_inv(h, mod); //h = h^-1 % mod

      //bit reverse
      int i = 0;
      for (int j = 1; j < n - 1; ++j) {
        for (int k = n >> 1; k >(i ^= k); k >>= 1);
        if (j < i) swap(a[i], a[j]);
      }

      for (int m = 1; m < n; m *= 2) {
        const int m2 = 2 * m;
        const ll base = mod_pow(h, n / m2, mod);
        ll w = 1;
        FOR(x, m) {
          for (int s = x; s < n; s += m2) {
            ll u = a[s];
            ll d = a[s + m] * w % mod;
            a[s] = u + d;
            if (a[s] >= mod) a[s] -= mod;
            a[s + m] = u - d;
            if (a[s + m] < 0) a[s + m] += mod;
          }
          w = w * base % mod;
        }
      }

      for (auto& x : a) if (x < 0) x += mod;
    }
    void ntt(vector<ll>& input) {
      _ntt(input, 1);
    }
    void intt(vector<ll>& input) {
      _ntt(input, -1);
      const int n_inv = mod_inv(sz(input), mod);
      for (auto& x : input) x = x * n_inv % mod;
    }

    // 畳み込み演算を行う
    vector<ll> convolution(const vector<ll>& a, const vector<ll>& b){
      int ntt_size = 1;
      while (ntt_size < sz(a) + sz(b)) ntt_size *= 2;

      vector<ll> _a = a, _b = b;
      _a.resize(ntt_size); _b.resize(ntt_size);

      ntt(_a);
      ntt(_b);

      FOR(i, ntt_size){
        (_a[i] *= _b[i]) %= mod;
      }

      intt(_a);
      return _a;
    }
};

ll garner(vector<Pii> mr, int mod){
  mr.emplace_back(mod, 0);

  vector<ll> coffs(sz(mr), 1);
  vector<ll> constants(sz(mr), 0);
  FOR(i, sz(mr) - 1){
    // coffs[i] * v + constants[i] == mr[i].second (mod mr[i].first) を解く
    ll v = (mr[i].second - constants[i]) * mod_inv<ll>(coffs[i], mr[i].first) % mr[i].first;
    if (v < 0) v += mr[i].first;

    for (int j = i + 1; j < sz(mr); j++) {
      (constants[j] += coffs[j] * v) %= mr[j].first;
      (coffs[j] *= mr[i].first) %= mr[j].first;
    }
  }

  return constants[sz(mr) - 1];
}

typedef NTT<167772161, 3> NTT_1;
typedef NTT<469762049, 3> NTT_2;
typedef NTT<1224736769, 3> NTT_3;

//任意のmodで畳み込み演算 O(n log n)
vector<ll> int32mod_convolution(vector<ll> a, vector<ll> b,int mod){
  for (auto& x : a) x %= mod;
  for (auto& x : b) x %= mod;
  NTT_1 ntt1; NTT_2 ntt2; NTT_3 ntt3;
  auto x = ntt1.convolution(a, b);
  auto y = ntt2.convolution(a, b);
  auto z = ntt3.convolution(a, b);

  vector<ll> ret(sz(x));
  vector<Pii> mr(3);
  FOR(i, sz(x)){
    mr[0].first = ntt1.get_mod(), mr[0].second = (int)x[i];
    mr[1].first = ntt2.get_mod(), mr[1].second = (int)y[i];
    mr[2].first = ntt3.get_mod(), mr[2].second = (int)z[i];
    ret[i] = garner(mr, mod);
  }

  return ret;
}

constexpr int MOD = 1000000007;

class mint {
  int n;
public:
  mint(int n_ = 0) : n(n_) {}
  explicit operator int() { return n; }
  friend mint operator-(mint a) { return -a.n + MOD * (a.n != 0); }
  friend mint operator+(mint a, mint b) { int x = a.n + b.n; return x - (x >= MOD) * MOD; }
  friend mint operator-(mint a, mint b) { int x = a.n - b.n; return x + (x < 0) * MOD; }
  friend mint operator*(mint a, mint b) { return (long long)a.n * b.n % MOD; }
  friend mint &operator+=(mint &a, mint b) { return a = a + b; }
  friend mint &operator-=(mint &a, mint b) { return a = a - b; }
  friend mint &operator*=(mint &a, mint b) { return a = a * b; }
  friend bool operator==(mint a, mint b) { return a.n == b.n; }
  friend bool operator!=(mint a, mint b) { return a.n != b.n; }
  friend istream &operator>>(istream &i, mint &a) { return i >> a.n; }
  friend ostream &operator<<(ostream &o, mint a) { return o << a.n; }
};


vector<mint> F_{1, 1}, R_{1, 1}, I_{0, 1};

void check_fact(int n) {
  for (int i = I_.size(); i <= n; i++) {
    I_.push_back(I_[MOD % i] * (MOD - MOD / i));
    F_.push_back(F_[i - 1] * i);
    R_.push_back(R_[i - 1] * I_[i]);
  }
}

mint I(int n) { check_fact(n); return n < 0 ? 0 : I_[n]; }
mint F(int n) { check_fact(n); return n < 0 ? 0 : F_[n]; }
mint R(int n) { check_fact(n); return n < 0 ? 0 : R_[n]; }
mint C(int n, int r) { return F(n) * R(n - r) * R(r); }
mint P(int n, int r) { return F(n) * R(n - r); }
mint H(int n, int r) { return n == 0 ? (r == 0) : C(n + r - 1, r); }

mint alt(int n) {
  return n % 2 == 0 ? 1 : MOD - 1;
}

int main() {
  int X, Y, Z; cin >> X >> Y >> Z;
  vector<ll> A(1 << 21);
  vector<ll> B(1 << 21);
  for (int i = 0; i < A.size(); i++) {
    A[i] = (int)(alt(i) * R(i));
    B[i] = (int)(R(i) * F(i + X - 1) * F(i + Y - 1) * F(i + Z - 1) * R(i - 1) * R(i - 1) * R(i - 1));
  }
  A = int32mod_convolution(A, B, MOD);
  mint ans = 0;
  rep(i, A.size() / 2) {
    ans += A[i] * F(i);
  }
  ans *= R(X) * R(Y) * R(Z);
  cout << ans << endl;

  /*
  {
  mint ans;
  for (int k = 0; k <= 8000; k++) {
    mint v;
    for (int i = 0; i <= k; i++) {
      int j = k - i;
      mint s = i % 2 == 0 ? 1 : MOD - 1;
      // ans += s * C(k, i) * H(k - i, X) * H(k - i, Y) * H(k - i, Z);
      mint tmp = s * R(i) * R(j);
      tmp *= F(j + X - 1) * R(j - 1);
      tmp *= F(j + Y - 1) * R(j - 1);
      tmp *= F(j + Z - 1) * R(j - 1);
      v += tmp;
    }
    ans += v * F(k);
  }
  ans *= R(X) * R(Y) * R(Z);
  cout << ans << endl;
  }
  */
}