#include <bits/stdc++.h>
// created [2019/12/02] 23:55:48
#pragma GCC diagnostic ignored "-Wsign-compare"
#pragma GCC diagnostic ignored "-Wsign-conversion"

using i32 = int32_t;
using i64 = int64_t;
using u32 = uint32_t;
using u64 = uint64_t;
using uint = unsigned int;
using usize = std::size_t;
using ll = long long;
using ull = unsigned long long;
using ld = long double;
template<typename T> constexpr T popcount(const T u) { return u ? static_cast<T>(__builtin_popcountll(static_cast<u64>(u))) : static_cast<T>(0); }
template<typename T> constexpr T log2p1(const T u) { return u ? static_cast<T>(64 - __builtin_clzll(static_cast<u64>(u))) : static_cast<T>(0); }
template<typename T> constexpr T msbp1(const T u) { return log2p1(u); }
template<typename T> constexpr T lsbp1(const T u) { return __builtin_ffsll(u); }
template<typename T> constexpr T clog(const T u) { return u ? log2p1(u - 1) : static_cast<T>(u); }
template<typename T> constexpr bool ispow2(const T u) { return u and (static_cast<u64>(u) & static_cast<u64>(u - 1)) == 0; }
template<typename T> constexpr T ceil2(const T u) { return static_cast<T>(1) << clog(u); }
template<typename T> constexpr T floor2(const T u) { return u == 0 ? static_cast<T>(0) : static_cast<T>(1) << (log2p1(u) - 1); }
template<typename T> constexpr bool btest(const T mask, const usize ind) { return static_cast<bool>((static_cast<u64>(mask) >> ind) & static_cast<u64>(1)); }
template<typename T> void bset(T& mask, const usize ind) { mask |= (static_cast<T>(1) << ind); }
template<typename T> void breset(T& mask, const usize ind) { mask &= ~(static_cast<T>(1) << ind); }
template<typename T> void bflip(T& mask, const usize ind) { mask ^= (static_cast<T>(1) << ind); }
template<typename T> void bset(T& mask, const usize ind, const bool b) { (b ? bset(mask, ind) : breset(mask, ind)); }
template<typename T> constexpr T bcut(const T mask, const usize ind) { return ind == 0 ? static_cast<T>(0) : static_cast<T>((static_cast<u64>(mask) << (64 - ind)) >> (64 - ind)); }
template<typename T> bool chmin(T& a, const T& b) { return (a > b ? a = b, true : false); }
template<typename T> bool chmax(T& a, const T& b) { return (a < b ? a = b, true : false); }
constexpr unsigned int mod                  = 1000000007;
template<typename T> constexpr T inf_v      = std::numeric_limits<T>::max() / 4;
template<typename Real> constexpr Real pi_v = Real{3.141592653589793238462643383279502884};

template<typename T>
T read()
{
    T v;
    return std::cin >> v, v;
}
template<typename T, typename... Args>
auto read(const usize size, Args... args)
{
    std::vector<decltype(read<T>(args...))> ans(size);
    for (usize i = 0; i < size; i++) { ans[i] = read<T>(args...); }
    return ans;
}
template<typename... Types>
auto reads() { return std::tuple<std::decay_t<Types>...>{read<Types>()...}; }
#    define SHOW(...) static_cast<void>(0)

template<typename T>
std::vector<T> make_v(const usize size, const T v) { return std::vector<T>(size, v); }
template<typename... Args>
auto make_v(const usize size, Args... args) { return std::vector<decltype(make_v(args...))>(size, make_v(args...)); }



template<typename T> T gcd(const T& a, const T& b) { return a < 0 ? gcd(-a, b) : b < 0 ? gcd(a, -b) : (a > b ? gcd(b, a) : a == 0 ? b : gcd(b % a, a)); }
template<typename T> T lcm(const T& a, const T& b) { return a / gcd(a, b) * b; }
template<typename T>
constexpr std::pair<T, T> extgcd(const T a, const T b)
{
    if (b == 0) { return std::pair<T, T>{1, 0}; }
    const auto g = gcd(a, b), da = std::abs(b) / g;
    const auto p = extgcd(b, a % b);
    const auto x = (da + p.second % da) % da, y = (g - a * x) / b;
    return {x, y};
}
template<typename T>
constexpr T inverse(const T a, const T mod) { return extgcd(a, mod).first; }
template<uint mod_value, bool dynamic = false>
class modint_base
{
public:
    template<typename UInt = uint>
    static std::enable_if_t<dynamic, const UInt> mod() { return mod_ref(); }
    template<typename UInt = uint>
    static constexpr std::enable_if_t<not dynamic, const UInt> mod() { return mod_value; }
    template<typename UInt = uint>
    static void set_mod(const std::enable_if_t<dynamic, const UInt> mod) { mod_ref() = mod, inv_ref() = {1, 1}; }
    modint_base() : v{0} {}
    modint_base(const ll val) : v{norm(static_cast<uint>(val % static_cast<ll>(mod()) + static_cast<ll>(mod())))} {}
    modint_base(const modint_base& n) : v{n()} {}
    explicit operator bool() const { return v != 0; }
    bool operator!() const { return not static_cast<bool>(*this); }
    modint_base& operator=(const modint_base& m) { return v = m(), (*this); }
    modint_base& operator=(const ll val) { return v = norm(uint(val % static_cast<ll>(mod()) + static_cast<ll>(mod()))), (*this); }
    friend modint_base operator+(const modint_base& m) { return m; }
    friend modint_base operator-(const modint_base& m) { return make(norm(mod() - m.v)); }
    friend modint_base operator+(const modint_base& m1, const modint_base& m2) { return make(norm(m1.v + m2.v)); }
    friend modint_base operator-(const modint_base& m1, const modint_base& m2) { return make(norm(m1.v + mod() - m2.v)); }
    friend modint_base operator*(const modint_base& m1, const modint_base& m2) { return make(static_cast<uint>(static_cast<ll>(m1.v) * static_cast<ll>(m2.v) % static_cast<ll>(mod()))); }
    friend modint_base operator/(const modint_base& m1, const modint_base& m2) { return m1 * inv(m2.v); }
    friend modint_base operator+(const modint_base& m, const ll val) { return modint_base{static_cast<ll>(m.v) + val}; }
    friend modint_base operator-(const modint_base& m, const ll val) { return modint_base{static_cast<ll>(m.v) - val}; }
    friend modint_base operator*(const modint_base& m, const ll val) { return modint_base{static_cast<ll>(m.v) * (val % static_cast<ll>(mod()))}; }
    friend modint_base operator/(const modint_base& m, const ll val) { return modint_base{static_cast<ll>(m.v) * inv(val)}; }
    friend modint_base operator+(const ll val, const modint_base& m) { return modint_base{static_cast<ll>(m.v) + val}; }
    friend modint_base operator-(const ll val, const modint_base& m) { return modint_base{-static_cast<ll>(m.v) + val}; }
    friend modint_base operator*(const ll val, const modint_base& m) { return modint_base{static_cast<ll>(m.v) * (val % static_cast<ll>(mod()))}; }
    friend modint_base operator/(const ll val, const modint_base& m) { return modint_base{val * inv(static_cast<ll>(m.v))}; }
    friend modint_base& operator+=(modint_base& m1, const modint_base& m2) { return m1 = m1 + m2; }
    friend modint_base& operator-=(modint_base& m1, const modint_base& m2) { return m1 = m1 - m2; }
    friend modint_base& operator*=(modint_base& m1, const modint_base& m2) { return m1 = m1 * m2; }
    friend modint_base& operator/=(modint_base& m1, const modint_base& m2) { return m1 = m1 / m2; }
    friend modint_base& operator+=(modint_base& m, const ll val) { return m = m + val; }
    friend modint_base& operator-=(modint_base& m, const ll val) { return m = m - val; }
    friend modint_base& operator*=(modint_base& m, const ll val) { return m = m * val; }
    friend modint_base& operator/=(modint_base& m, const ll val) { return m = m / val; }
    friend modint_base operator^(const modint_base& m, const ll n) { return power(m.v, n); }
    friend modint_base& operator^=(modint_base& m, const ll n) { return m = m ^ n; }
    friend bool operator==(const modint_base& m1, const modint_base& m2) { return m1.v == m2.v; }
    friend bool operator!=(const modint_base& m1, const modint_base& m2) { return not(m1 == m2); }
    friend bool operator==(const modint_base& m, const ll val) { return m.v == norm(static_cast<uint>(static_cast<ll>(mod()) + val % static_cast<ll>(mod()))); }
    friend bool operator!=(const modint_base& m, const ll val) { return not(m == val); }
    friend bool operator==(const ll val, const modint_base& m) { return m.v == norm(static_cast<uint>(static_cast<ll>(mod()) + val % static_cast<ll>(mod()))); }
    friend bool operator!=(const ll val, const modint_base& m) { return not(m == val); }
    friend std::istream& operator>>(std::istream& is, modint_base& m)
    {
        ll v;
        return is >> v, m = v, is;
    }
    friend std::ostream& operator<<(std::ostream& os, const modint_base& m) { return os << m(); }
    uint operator()() const { return v; }
    static modint_base small_inv(const usize n)
    {
        auto& in = inv_ref();
        if (n < in.size()) { return in[n]; }
        for (usize i = in.size(); i <= n; i++) { in.push_back(-in[modint_base::mod() % i] * (modint_base::mod() / i)); }
        return in.back();
    }

private:
    template<typename UInt = uint>
    static std::enable_if_t<dynamic, UInt&> mod_ref()
    {
        static UInt mod = 0;
        return mod;
    }
    static uint norm(const uint x) { return x < mod() ? x : x - mod(); }
    static modint_base make(const uint x)
    {
        modint_base m;
        return m.v = x, m;
    }
    static modint_base power(modint_base x, ull n)
    {
        modint_base ans = 1;
        for (; n; n >>= 1, x *= x) {
            if (n & 1) { ans *= x; }
        }
        return ans;
    }
    static modint_base inv(const ll v) { return v < 1000000 ? small_inv(static_cast<usize>(v)) : modint_base{inverse(v, static_cast<ll>(mod()))}; }
    static std::vector<modint_base>& inv_ref()
    {
        static std::vector<modint_base> in{1, 1};
        return in;
    }
    uint v;
};
template<uint mod>
using modint = modint_base<mod, false>;
template<uint id>
using dynamic_modint = modint_base<id, true>;
template<uint mod_value, bool dynamic = false>
class modcomb_base
{
public:
    using value_type = modint_base<mod_value, dynamic>;
    modcomb_base()   = delete;
    static void set_mod(const uint mod) { value_type::set_mod(mod), fact_ref() = {1, 1}, inv_fact_ref() = {1, 1}; }
    static value_type fact(const usize n)
    {
        auto& f = fact_ref();
        if (n < f.size()) { return f[n]; }
        for (usize i = f.size(); i <= n; i++) { f.push_back(f.back() * i); }
        return f.back();
    }
    static value_type inv_fact(const usize n)
    {
        auto& invf = inv_fact_ref();
        if (n < invf.size()) { return invf[n]; }
        for (usize i = invf.size(); i <= n; i++) { invf.push_back(invf.back() * value_type::small_inv(i)); }
        return invf.back();
    }
    static value_type perm(const usize n, const usize k) { return k > n ? value_type{0} : fact(n) * inv_fact(n - k); }
    static value_type comb(const usize n, const usize k) { return k > n ? value_type{0} : fact(n) * inv_fact(n - k) * inv_fact(k); }

private:
    static std::vector<value_type>& fact_ref()
    {
        static std::vector<value_type> f{1, 1};
        return f;
    }
    static std::vector<value_type>& inv_fact_ref()
    {
        static std::vector<value_type> invf{1, 1};
        return invf;
    }
};
template<uint mod>
using modcomb = modcomb_base<mod, false>;
template<uint id>
using dynamic_modcomb = modcomb_base<id, true>;

template<typename Real>
struct complex
{
    using value_type = Real;
    complex() : real{Real{0}}, imag{Real{0}} {}
    complex(const complex&) = default;
    complex(const Real& theta) : real(std::cos(theta)), imag(std::sin(theta)) {}
    complex(const Real& r, const Real& i) : real{r}, imag{i} {}
    ~complex() = default;
    friend complex operator+(const complex& c) { return c; }
    friend complex operator-(const complex& c) { return complex{-c.real, -c.imag}; }
    friend complex operator+(const complex& c1, const complex& c2) { return complex{c1.real + c2.real, c1.imag + c2.imag}; }
    friend complex operator-(const complex& c1, const complex& c2) { return complex{c1.real - c2.real, c1.imag - c2.imag}; }
    friend complex operator*(const complex& c1, const complex& c2) { return complex{c1.real * c2.real - c1.imag * c2.imag, c1.real * c2.imag + c1.imag * c2.real}; }
    friend complex operator*(const complex& c, const Real& r) { return complex{c.real * r, c.imag * r}; }
    friend complex operator/(complex& c1, complex& c2) { c1* c2.conj() / c2.norm(); }
    friend bool operator==(const complex& c1, const complex& c2) { return c1.real == c2.real and c1.imag == c2.imag; }
    friend bool operator!=(const complex& c1, const complex& c2) { return not(c1 == c2); }
    friend complex& operator+=(complex& c1, const complex& c2) { return c1.real += c2.real, c1.imag += c2.imag, c1; }
    friend complex& operator-=(complex& c1, const complex& c2) { return c1.real += c2.real, c1.imag += c2.imag, c1; }
    friend complex& operator*=(complex& c1, const complex& c2) { return c1 = c1 * c2; }
    friend complex& operator*=(complex& c, const Real& r) { return c = c * r; }
    friend complex& operator/=(complex& c1, const complex& c2) { return c1 = c1 / c2; }
    complex conj() const { return complex{real, -imag}; }
    Real norm() const { return real * real + imag * imag; }
    Real abs() const { return std::sqrt(norm()); }
    Real arg() const { return std::atan2(imag, real); }
    friend std::ostream& operator<<(std::ostream& os, const complex& c) { return os << c.real << "+" << c.imag << "i"; }
    Real real, imag;
};
template<typename Real = double>
class fft
{
private:
    static constexpr usize depth = 30;
    static constexpr Real pi     = pi_v<Real>;
    static void transform(std::vector<complex<Real>>& a, const usize lg, const bool rev)
    {
        static std::vector<complex<Real>> root[depth];
        const usize sz = a.size();
        assert((1UL << lg) == sz);
        if (root[lg].empty()) {
            root[lg].reserve(sz), root[lg].resize(sz);
            for (usize i = 0; i < sz; i++) { root[lg][i] = complex<Real>(pi * Real(2 * i) / Real(sz)); }
        }
        std::vector<complex<Real>> tmp(sz);
        for (usize w = (sz >> 1); w > 0; w >>= 1) {
            for (usize y = 0; y < (sz >> 1); y += w) {
                const complex<Real> r = rev ? root[lg][y].conj() : root[lg][y];
                for (usize x = 0; x < w; x++) {
                    const auto u = a[y << 1 | x], v = a[y << 1 | x | w] * r;
                    tmp[y | x] = u + v, tmp[y | x | (sz >> 1)] = u - v;
                }
            }
            std::swap(tmp, a);
        }
    }

public:
    using value_type = Real;
    fft()            = delete;
    template<typename T = ll, typename I = int>
    static std::vector<T> simple_convolute(const std::vector<I>& a, const std::vector<I>& b)
    {
        const usize need = a.size() + b.size() - 1, lg = clog(need), sz = 1UL << lg;
        std::vector<complex<Real>> x(sz), y(sz);
        for (usize i = 0; i < a.size(); i++) { x[i] = {(Real)a[i], (Real)0}; }
        for (usize i = 0; i < b.size(); i++) { y[i] = {(Real)b[i], (Real)0}; }
        transform(x, lg, false), transform(y, lg, false);
        for (usize i = 0; i < sz; i++) { x[i] *= y[i]; }
        transform(x, lg, true);
        std::vector<T> ans(need);
        for (usize i = 0; i < need; i++) { ans[i] = (T)std::round(x[i].real / (Real)sz); }
        return ans;
    }
    template<typename T = ll, usize division = 2, typename I = int>
    static std::vector<T> convolute(const std::vector<I>& a, const std::vector<I>& b)
    {
        constexpr usize bitnum = (depth + division - 1) / division;
        const usize need = a.size() + b.size() - 1, lg = clog(need), sz = 1UL << lg;
        std::vector<complex<value_type>> x[division], y[division], tmp(sz);
        for (usize i = 0; i < division; i++) {
            x[i].reserve(sz), x[i].resize(sz), y[i].reserve(sz), y[i].resize(sz);
            std::fill(tmp.begin() + std::min(a.size(), b.size()), tmp.end(), complex<value_type>{});
            for (usize j = 0; j < a.size(); j++) { tmp[j].real = value_type((a[j] >> (bitnum * i)) & ((1 << bitnum) - 1)); }
            for (usize j = 0; j < b.size(); j++) { tmp[j].imag = value_type((b[j] >> (bitnum * i)) & ((1 << bitnum) - 1)); }
            transform(tmp, lg, false);
            for (usize j = 0; j < sz; j++) { tmp[j] *= value_type(0.5); }
            for (usize j = 0; j < sz; j++) {
                const usize k = j == 0 ? 0UL : sz - j;
                x[i][j] = complex<value_type>{tmp[j].real + tmp[k].real, tmp[j].imag - tmp[k].imag}, y[i][j] = complex<value_type>{tmp[j].imag + tmp[k].imag, -tmp[j].real + tmp[k].real};
            }
        }
        std::vector<complex<value_type>> z[division];
        for (usize i = 0; i < division; i++) { z[i].reserve(sz), z[i].resize(sz); }
        for (usize a = 0; a < division; a++) {
            for (usize b = 0; b < division; b++) {
                for (usize i = 0; i < sz; i++) {
                    if (a + b < division) {
                        z[a + b][i] += x[a][i] * y[b][i];
                    } else {
                        z[a + b - division][i] += x[a][i] * y[b][i] * complex<value_type>(0, 1);
                    }
                }
            }
        }
        for (usize i = 0; i < division; i++) { transform(z[i], lg, true); }
        std::vector<T> ans(need);
        T base = 1;
        for (usize k = 0; k < 2 * division - 1; k++, base *= (1LL << bitnum)) {
            for (usize i = 0; i < need; i++) {
                if (k < division) {
                    ans[i] += base * T(std::round(z[k][i].real / value_type(sz)));
                } else {
                    ans[i] += base * T(std::round(z[k - division][i].imag / value_type(sz)));
                }
            }
        }
        return ans;
    }
    template<uint mod, bool dynamic = false, usize division = 2>
    static std::vector<modint_base<mod, dynamic>> convolute(const std::vector<modint_base<mod, dynamic>>& a, const std::vector<modint_base<mod, dynamic>>& b)
    {
        using mint             = modint_base<mod, dynamic>;
        constexpr usize bitnum = (depth + division - 1) / division;
        const usize need = a.size() + b.size() - 1, lg = clog(need), sz = 1UL << lg;
        std::vector<complex<value_type>> x[division], y[division], tmp(sz);
        for (usize i = 0; i < division; i++) {
            x[i].reserve(sz), x[i].resize(sz), y[i].reserve(sz), y[i].resize(sz);
            std::fill(tmp.begin() + std::min(a.size(), b.size()), tmp.end(), complex<value_type>{});
            for (usize j = 0; j < a.size(); j++) { tmp[j].real = value_type((a[j]() >> (bitnum * i)) & ((1 << bitnum) - 1)); }
            for (usize j = 0; j < b.size(); j++) { tmp[j].imag = value_type((b[j]() >> (bitnum * i)) & ((1 << bitnum) - 1)); }
            transform(tmp, lg, false);
            for (usize j = 0; j < sz; j++) { tmp[j] *= value_type(0.5); }
            for (usize j = 0; j < sz; j++) {
                const usize k = j == 0 ? 0UL : sz - j;
                x[i][j] = complex<value_type>{tmp[j].real + tmp[k].real, tmp[j].imag - tmp[k].imag}, y[i][j] = complex<value_type>{tmp[j].imag + tmp[k].imag, -tmp[j].real + tmp[k].real};
            }
        }
        std::vector<complex<value_type>> z[division];
        for (usize i = 0; i < division; i++) { z[i].reserve(sz), z[i].resize(sz); }
        for (usize a = 0; a < division; a++) {
            for (usize b = 0; b < division; b++) {
                for (usize i = 0; i < sz; i++) {
                    if (a + b < division) {
                        z[a + b][i] += x[a][i] * y[b][i];
                    } else {
                        z[a + b - division][i] += x[a][i] * y[b][i] * complex<value_type>(0, 1);
                    }
                }
            }
        }
        for (usize i = 0; i < division; i++) { transform(z[i], lg, true); }
        std::vector<mint> ans(need);
        mint base = 1;
        for (usize k = 0; k < 2 * division - 1; k++, base *= (1LL << bitnum)) {
            for (usize i = 0; i < need; i++) {
                if (k < division) {
                    ans[i] += int((base * ll(std::round(z[k][i].real / value_type(sz))))());
                } else {
                    ans[i] += int((base * ll(std::round(z[k - division][i].imag / value_type(sz))))());
                }
            }
        }
        return ans;
    }
};
int main()
{
    using mint           = modint<mod>;
    using moc            = modcomb<mod>;
    const auto [X, Y, Z] = reads<int, int, int>();
    const int T          = X + Y + Z;
    if (T == 0) { return std::cout << 1 << std::endl, 0; }
    std::vector<mint> sum(T + 1, 0);
    for (int i = 1; i <= T; i++) {
        sum[i] = moc::comb(X + i - 1, X) * moc::comb(Y + i - 1, Y) * moc::comb(Z + i - 1, Z);
        sum[i] *= moc::inv_fact(i);
    }
    std::vector<mint> diff(T + 1, 0);
    for (int i = 0; i <= T; i++) { diff[i] = moc::inv_fact(i) * (i % 2 == 0 ? 1 : -1); }
    auto res = fft<>::convolute(sum, diff);
    mint ans = 0;
    for (int i = 0; i <= T; i++) { ans += res[i] * moc::fact(i); }
    std::cout << ans << std::endl;

    return 0;
}