#include <bits/stdc++.h>
using namespace std;

// Define
using ll = long long;
using ull = unsigned long long;
using ld = long double;
template <class T> using pvector = vector<pair<T, T>>;
template <class T>
using rpriority_queue = priority_queue<T, vector<T>, greater<T>>;
constexpr const ll dx[4] = {1, 0, -1, 0};
constexpr const ll dy[4] = {0, 1, 0, -1};
constexpr const ll MOD = 1e9 + 7;
constexpr const ll mod = 998244353;
constexpr const ll INF = 1LL << 60;
constexpr const ll inf = 1 << 30;
constexpr const char rt = '\n';
constexpr const char sp = ' ';
#define mp make_pair
#define mt make_tuple
#define pb push_back
#define eb emplase_back
#define elif else if
#define all(a, v, ...)                                                         \
    ([&](decltype((v)) w) { return (a)(begin(w), end(w), ##__VA_ARGS__); })(v)
#define fi first
#define se second

template <class T> bool chmax(T &a, const T &b) {
    if (a < b) {
        a = b;
        return 1;
    }
    return 0;
}
template <class T> bool chmin(T &a, const T &b) {
    if (a > b) {
        a = b;
        return 1;
    }
    return 0;
}

// Debug
#define debug(...)                                                             \
    {                                                                          \
        cerr << __LINE__ << ": " << #__VA_ARGS__ << " = ";                     \
        for (auto &&X : {__VA_ARGS__}) cerr << "[" << X << "] ";               \
        cerr << rt;                                                            \
    }

#define dump(a, h, w)                                                          \
    {                                                                          \
        cerr << __LINE__ << ": " << #a << " = [" << rt;                        \
        rep(i, h) {                                                            \
            rep(j, w) cerr << a[i][j] << sp;                                   \
            cerr << rt;                                                        \
        }                                                                      \
        cerr << "]" << rt;                                                     \
    }

#define vdump(a, n)                                                            \
    {                                                                          \
        cerr << __LINE__ << ": " << #a << " = [";                              \
        rep(i, n) cerr << a[i] << (i == n - 1 ? rt : sp);                      \
        cerr << "]" << rt;                                                     \
    }

// Loop
#define inc(i, a, n) for (ll i = (a), _##i = (n); i <= _##i; ++i)
#define dec(i, a, n) for (ll i = (a), _##i = (n); i >= _##i; --i)
#define rep(i, n) for (ll i = 0, _##i = (n); i < _##i; ++i)
#define each(i, a) for (auto &&i : a)

// Stream
#define fout(n) cout << fixed << setprecision(n)
struct io {
    io() { cin.tie(nullptr), ios::sync_with_stdio(false); }
} io;

// Speed
#pragma GCC optimize("Ofast")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")

// Math
inline constexpr ll gcd(const ll a, const ll b) {
    return b ? gcd(b, a % b) : a;
}
inline constexpr ll lcm(const ll a, const ll b) { return a / gcd(a, b) * b; }

inline constexpr ll modulo(const ll n, const ll m = MOD) {
    ll k = n % m;
    return k + m * (k < 0);
}
inline constexpr ll chmod(ll &n, const ll m = MOD) {
    n %= m;
    return n += m * (n < 0);
}
inline constexpr ll mpow(ll a, ll n, const ll m = MOD) {
    ll r = 1;
    rep(i, 64) {
        if (n & (1LL << i)) r *= a;
        chmod(r, m);
        a *= a;
        chmod(a, m);
    }
    return r;
}
inline ll inv(const ll n, const ll m = MOD) {
    ll a = n, b = m, x = 1, y = 0;
    while (b) {
        ll t = a / b;
        a -= t * b;
        swap(a, b);
        x -= t * y;
        swap(x, y);
    }
    return modulo(x, m);
}

template <ull mod = MOD> struct mi {
    inline constexpr ll modulo(const ll n, const ll m) const noexcept {
        ll k = n % m;
        return k + m * (k < 0);
    }

    ll num;
    inline constexpr mi() noexcept : num() { num = 0; }
    inline constexpr mi(const int n) noexcept : num() { num = modulo(n, mod); }
    inline constexpr mi(const ll n) noexcept : num() { num = modulo(n, mod); }

    inline constexpr mi<mod> inv() const noexcept {
        ll a = num, b = mod, x = 1, y = 0;
        while (b) {
            ll t = a / b;
            a -= t * b;
            swap(a, b);
            x -= t * y;
            swap(x, y);
        }
        return mi<mod>(x);
    }
    inline constexpr mi<mod> inv(ll n) const noexcept {
        ll a = n, b = mod, x = 1, y = 0;
        while (b) {
            ll t = a / b;
            a -= t * b;
            swap(a, b);
            x -= t * y;
            swap(x, y);
        }
        return mi<mod>(x);
    }
    inline constexpr mi<mod> inv(const mi<mod> m) const noexcept {
        return inv(m.num);
    }

    inline constexpr mi<mod> operator+() const noexcept { return mi(num); }
    inline constexpr mi<mod> operator+(const int n) const noexcept {
        return mi<mod>(num + n);
    }
    inline constexpr mi<mod> operator+(const ll n) const noexcept {
        return mi<mod>(num + n);
    }
    inline constexpr mi<mod> operator+(const mi<mod> m) const noexcept {
        return mi<mod>(num + m.num);
    }
    inline constexpr mi<mod> operator-() const noexcept { return -num; }
    inline constexpr mi<mod> operator-(const int n) const noexcept {
        return mi<mod>(num - n);
    }
    inline constexpr mi<mod> operator-(const ll n) const noexcept {
        return mi<mod>(num - n);
    }
    inline constexpr mi<mod> operator-(const mi<mod> m) const noexcept {
        return mi<mod>(num - m.num);
    }
    inline constexpr mi<mod> operator*(const int n) const noexcept {
        return mi<mod>(num * n);
    }
    inline constexpr mi<mod> operator*(const ll n) const noexcept {
        return mi<mod>(num * n);
    }
    inline constexpr mi<mod> operator*(const mi<mod> m) const noexcept {
        return mi<mod>(num * m);
    }
    inline constexpr mi<mod> operator/(const int n) const noexcept {
        return mi<mod>(num * (ll) inv(n));
    }
    inline constexpr mi<mod> operator/(const ll n) const noexcept {
        return mi<mod>(num * (ll) inv(n));
    }
    inline constexpr mi<mod> operator/(const mi<mod> m) const noexcept {
        return mi<mod>(num * (ll) inv(m));
    }
    inline constexpr mi<mod> &operator=(const int n) noexcept {
        num = modulo(n, mod);
        return *this;
    }
    inline constexpr mi<mod> &operator=(const ll n) noexcept {
        num = modulo(n, mod);
        return *this;
    }
    inline constexpr mi<mod> &operator=(const mi<mod> m) noexcept {
        num = m.num;
        return *this;
    }
    inline constexpr mi<mod> &operator+=(const int n) noexcept {
        num = modulo(num + n, mod);
        return *this;
    }
    inline constexpr mi<mod> &operator+=(const ll n) noexcept {
        num = modulo(num + n, mod);
        return *this;
    }
    inline constexpr mi<mod> &operator+=(const mi<mod> m) noexcept {
        num = modulo(num + m.num, mod);
        return *this;
    }
    inline constexpr mi<mod> &operator++() noexcept {
        num = modulo(num + 1, mod);
        return *this;
    }
    inline constexpr mi<mod> operator++(int) noexcept {
        mi &pre = *this;
        num = modulo(num + 1, mod);
        return pre;
    }
    inline constexpr mi<mod> &operator-=(const int n) noexcept {
        num = modulo(num - n, mod);
        return *this;
    }
    inline constexpr mi<mod> &operator-=(const ll n) noexcept {
        num = modulo(num - n, mod);
        return *this;
    }
    inline constexpr mi<mod> &operator-=(const mi<mod> m) noexcept {
        num = modulo(num - m.num, mod);
        return *this;
    }
    inline constexpr mi<mod> &operator--() noexcept {
        num = modulo(num - 1, mod);
        return *this;
    }
    inline constexpr mi<mod> operator--(int) noexcept {
        mi &pre = *this;
        num = modulo(num - 1, mod);
        return pre;
    }
    inline constexpr mi<mod> &operator*=(const int n) noexcept {
        num = modulo(num * n, mod);
        return *this;
    }
    inline constexpr mi<mod> &operator*=(const ll n) noexcept {
        num = modulo(num * n, mod);
        return *this;
    }
    inline constexpr mi<mod> &operator*=(const mi<mod> m) noexcept {
        num = modulo(num * m.num, mod);
        return *this;
    }
    inline constexpr mi<mod> &operator/=(const int n) noexcept {
        num = modulo(num * (ll) inv(n), mod);
        return *this;
    }
    inline constexpr mi<mod> &operator/=(const ll n) noexcept {
        num = modulo(num * (ll) inv(n), mod);
        return *this;
    }
    inline constexpr mi<mod> &operator/=(const mi<mod> m) noexcept {
        num = modulo(num * (ll) inv(m), mod);
        return *this;
    }
    inline constexpr bool operator==(const int n) const noexcept {
        return num == modulo(n, mod);
    }
    inline constexpr bool operator==(const ll n) const noexcept {
        return num == modulo(n, mod);
    }
    inline constexpr bool operator==(const mi<mod> m) const noexcept {
        return num == m.num;
    }
    inline constexpr bool operator!=(const int n) const noexcept {
        return num != modulo(n, mod);
    }
    inline constexpr bool operator!=(const ll n) const noexcept {
        return num != modulo(n, mod);
    }
    inline constexpr bool operator!=(const mi<mod> m) const noexcept {
        return num != m.num;
    }
    constexpr operator int() const noexcept { return num; }
    constexpr operator ll() const noexcept { return num; }
    friend std::istream &operator>>(std::istream &, const mi<> &);
    friend std::ostream &operator<<(std::ostream &, const mi<> &);
};

template <ull mod = MOD>
inline constexpr mi<mod> operator+(const int n, const mi<mod> m) noexcept {
    return mi<mod>(n + m.num);
}
template <ull mod = MOD>
inline constexpr mi<mod> operator+(const ll n, const mi<mod> m) noexcept {
    return mi<mod>(n + m.num);
}
template <ull mod = MOD>
inline constexpr mi<mod> operator-(const int n, const mi<mod> m) noexcept {
    return mi<mod>(n - m.num);
}
template <ull mod = MOD>
inline constexpr mi<mod> operator-(const ll n, const mi<mod> m) noexcept {
    return mi<mod>(n - m.num);
}
template <ull mod = MOD>
inline constexpr mi<mod> operator*(const int n, const mi<mod> m) noexcept {
    return mi<mod>(n * m.num);
}
template <ull mod = MOD>
inline constexpr mi<mod> operator*(const ll n, const mi<mod> m) noexcept {
    return mi<mod>(n * m.num);
}
template <ull mod = MOD>
inline constexpr mi<mod> operator/(const int n, const mi<mod> m) noexcept {
    return mi<mod>(n * (ll) m.inv());
}
template <ull mod = MOD>
inline constexpr mi<mod> operator/(const ll n, const mi<mod> m) noexcept {
    return mi<mod>(n * (ll) m.inv());
}
inline constexpr mi<MOD> operator""_m(ull n) { return mi<MOD>((ll) n); }

template <ull mod = MOD>
inline constexpr mi<mod> pow(mi<mod> m, ll n) noexcept {
    mi<mod> r = mi<mod>(1);
    rep(i, 64) {
        if (n & (1LL << i)) r *= m;
        m *= m;
    }
    return r;
}
template <ull mod> istream &operator>>(istream &is, mi<mod> &m) {
    is >> m.num;
    return is;
}
template <ull mod> ostream &operator<<(ostream &is, mi<mod> &m) {
    is << (ll) m;
    return is;
}

template <ull mod = MOD> struct modmath {
    ll max;
    vector<mi<mod>> fac, inv;
    modmath() : max(1 << 20), fac(max + 1), inv(max + 1) {
        fac[0] = mi<mod>(1);
        rep(i, max) fac[i + 1] = fac[i] * (i + 1);
        inv[max] = fac[max].inv();
        dec(i, max - 1, 0) inv[i] = inv[i + 1] * (i + 1);
    }
    modmath(ll n) : max(n), fac(n + 1), inv(n + 1) {
        fac[0] = 1;
        rep(i, n) fac[i + 1] = fac[i] * (i + 1);
        inv[n] = 1 / fac[n];
        dec(i, n - 1, 0) inv[i] = inv[i + 1] * (i + 1);
    }

    inline mi<mod> fact(ll n) {
        if (n < 0) return mi<mod>(0);
        return fac[n];
    }
    inline mi<mod> perm(ll n, ll r) {
        if (r < 0 || n < r) return mi<mod>(0);
        return fac[n] * inv[n - r];
    }
    inline mi<mod> comb(ll n, ll r) {
        if (r < 0 || n < r) return mi<mod>(0);
        return fac[n] * inv[r] * inv[n - r];
    }
    inline mi<mod> nHr(ll n, ll r) { return comb(n + r - 1, n - 1); }
};
namespace FastFourierTransform {
using real = long double;

struct C {
    real x, y;

    C() : x(0), y(0) {}

    C(real x, real y) : x(x), y(y) {}

    inline C operator+(const C &c) const { return C(x + c.x, y + c.y); }

    inline C operator-(const C &c) const { return C(x - c.x, y - c.y); }

    inline C operator*(const C &c) const {
        return C(x * c.x - y * c.y, x * c.y + y * c.x);
    }

    inline C conj() const { return C(x, -y); }
};

const real PI = acosl(-1);
int base = 1;
vector<C> rts = {{0, 0}, {1, 0}};
vector<int> rev = {0, 1};

void ensure_base(int nbase) {
    if (nbase <= base) return;
    rev.resize(1 << nbase);
    rts.resize(1 << nbase);
    for (int i = 0; i < (1 << nbase); i++) {
        rev[i] = (rev[i >> 1] >> 1) + ((i & 1) << (nbase - 1));
    }
    while (base < nbase) {
        real angle = PI * 2.0 / (1 << (base + 1));
        for (int i = 1 << (base - 1); i < (1 << base); i++) {
            rts[i << 1] = rts[i];
            real angle_i = angle * (2 * i + 1 - (1 << base));
            rts[(i << 1) + 1] = C(cos(angle_i), sin(angle_i));
        }
        ++base;
    }
}

void fft(vector<C> &a, int n) {
    assert((n & (n - 1)) == 0);
    int zeros = __builtin_ctz(n);
    ensure_base(zeros);
    int shift = base - zeros;
    for (int i = 0; i < n; i++) {
        if (i < (rev[i] >> shift)) {
            swap(a[i], a[rev[i] >> shift]);
        }
    }
    for (int k = 1; k < n; k <<= 1) {
        for (int i = 0; i < n; i += 2 * k) {
            for (int j = 0; j < k; j++) {
                C z = a[i + j + k] * rts[j + k];
                a[i + j + k] = a[i + j] - z;
                a[i + j] = a[i + j] + z;
            }
        }
    }
}

vector<int64_t> multiply(const vector<int> &a, const vector<int> &b) {
    int need = (int) a.size() + (int) b.size() - 1;
    int nbase = 1;
    while ((1 << nbase) < need) nbase++;
    ensure_base(nbase);
    int sz = 1 << nbase;
    vector<C> fa(sz);
    for (int i = 0; i < sz; i++) {
        int x = (i < (int) a.size() ? a[i] : 0);
        int y = (i < (int) b.size() ? b[i] : 0);
        fa[i] = C(x, y);
    }
    fft(fa, sz);
    C r(0, -0.25 / (sz >> 1)), s(0, 1), t(0.5, 0);
    for (int i = 0; i <= (sz >> 1); i++) {
        int j = (sz - i) & (sz - 1);
        C z = (fa[j] * fa[j] - (fa[i] * fa[i]).conj()) * r;
        fa[j] = (fa[i] * fa[i] - (fa[j] * fa[j]).conj()) * r;
        fa[i] = z;
    }
    for (int i = 0; i < (sz >> 1); i++) {
        C A0 = (fa[i] + fa[i + (sz >> 1)]) * t;
        C A1 = (fa[i] - fa[i + (sz >> 1)]) * t * rts[(sz >> 1) + i];
        fa[i] = A0 + A1 * s;
    }
    fft(fa, sz >> 1);
    vector<int64_t> ret(need);
    for (int i = 0; i < need; i++) {
        ret[i] = llround(i & 1 ? fa[i >> 1].y : fa[i >> 1].x);
    }
    return ret;
}
}; // namespace FastFourierTransform

template <typename T> struct ArbitraryModConvolution {
    using real = FastFourierTransform::real;
    using C = FastFourierTransform::C;

    ArbitraryModConvolution() = default;

    vector<T> multiply(const vector<T> &a, const vector<T> &b, int need = -1) {
        if (need == -1) need = a.size() + b.size() - 1;
        int nbase = 0;
        while ((1 << nbase) < need) nbase++;
        FastFourierTransform::ensure_base(nbase);
        int sz = 1 << nbase;
        vector<C> fa(sz);
        for (int i = 0; i < a.size(); i++) {
            fa[i] = C(a[i].num & ((1 << 15) - 1), a[i].num >> 15);
        }
        fft(fa, sz);
        vector<C> fb(sz);
        if (a == b) {
            fb = fa;
        } else {
            for (int i = 0; i < b.size(); i++) {
                fb[i] = C(b[i].num & ((1 << 15) - 1), b[i].num >> 15);
            }
            fft(fb, sz);
        }
        real ratio = 0.25 / sz;
        C r2(0, -1), r3(ratio, 0), r4(0, -ratio), r5(0, 1);
        for (int i = 0; i <= (sz >> 1); i++) {
            int j = (sz - i) & (sz - 1);
            C a1 = (fa[i] + fa[j].conj());
            C a2 = (fa[i] - fa[j].conj()) * r2;
            C b1 = (fb[i] + fb[j].conj()) * r3;
            C b2 = (fb[i] - fb[j].conj()) * r4;
            if (i != j) {
                C c1 = (fa[j] + fa[i].conj());
                C c2 = (fa[j] - fa[i].conj()) * r2;
                C d1 = (fb[j] + fb[i].conj()) * r3;
                C d2 = (fb[j] - fb[i].conj()) * r4;
                fa[i] = c1 * d1 + c2 * d2 * r5;
                fb[i] = c1 * d2 + c2 * d1;
            }
            fa[j] = a1 * b1 + a2 * b2 * r5;
            fb[j] = a1 * b2 + a2 * b1;
        }
        fft(fa, sz);
        fft(fb, sz);
        vector<T> ret(need);
        for (int i = 0; i < need; i++) {
            ll aa = llround(fa[i].x);
            ll bb = llround(fb[i].x);
            ll cc = llround(fa[i].y);
            aa = T(aa).num, bb = T(bb).num, cc = T(cc).num;
            ret[i] = aa + (bb << 15) + (cc << 30);
        }
        return ret;
    }
};
// thanks to ei1333

signed main() {
    ll n, x, y, z;
    cin >> x >> y >> z;
    n = x + y + z;
    if (n == 0) return puts("1") & 0;
    mi<> res;
    vector<mi<>> a(n), b(n), A035317;
    modmath<> m(1 << 21);
#define M(i)                                                                   \
    (m.comb(x + i - 1, x) * m.comb(y + i - 1, y) * m.comb(z + i - 1, z))
    rep(i, n) a[i] = (i & 1 ? -1 : 1) / m.fact(i);
    rep(i, n) b[i] = m.fact(n - i);
    ArbitraryModConvolution<mi<>> FFT;
    A035317 = FFT.multiply(a, b);
    rep(i, n) res += M(n - i) * A035317[i] / m.fact(n - i);
    cout << res << rt;
}

// -g -D_GLIBCXX_DEBUG -fsanitize=undefined