#ifdef stderr_path
#define LOCAL
#endif
#ifdef LOCAL
#define _GLIBCXX_DEBUG
#else
#pragma GCC optimize("Ofast")
#endif
#include <algorithm>
#include <bitset>
#include <cassert>
#include <chrono>
#include <complex>
#include <cstring>
#include <deque>
#include <functional>
#include <iomanip>
#include <iostream>
#include <map>
#include <queue>
#include <random>
#include <set>
#include <stack>
#include <unordered_map>
#include <unordered_set>

// #define NDEBUG
#define debug_stream std::cerr
#define iostream_untie true
#define __precision__ 10

#define all(v) std::begin(v), std::end(v)
#define rall(v) std::rbegin(v), std::rend(v)
#define __odd(n) ((n)&1)
#define __even(n) (not __odd(n))
#define __popcount(n) __builtin_popcountll(n)
#define __clz32(n) __builtin_clz(n)
#define __clz64(n) __builtin_clzll(n)
#define __ctz32(n) __builtin_ctz(n)
#define __ctz64(n) __builtin_ctzll(n)

using i64 = int_fast64_t;
using pii = std::pair<int, int>;
using pll = std::pair<int_fast64_t, int_fast64_t>;
template <class T>
using heap = std::priority_queue<T>;
template <class T>
using minheap = std::priority_queue<T, std::vector<T>, std::greater<T>>;
template <class T>
constexpr T inf = std::numeric_limits<T>::max() / T(2) - T(1123456);

namespace execution
{
    std::chrono::system_clock::time_point start_time, end_time;
    void print_elapsed_time()
    {
        end_time = std::chrono::system_clock::now();
        std::cerr << "\n----- Exec time : ";
        std::cerr << std::chrono::duration_cast<std::chrono::milliseconds>(
                        end_time - start_time)
                        .count();
        std::cerr << " ms -----\n\n";
    }
    struct setupper
    {
        setupper()
        {
            if(iostream_untie)
            {
                std::ios::sync_with_stdio(false);
                std::cin.tie(nullptr);
            }
            std::cout << std::fixed << std::setprecision(__precision__);
#ifdef stderr_path
            if(freopen(stderr_path, "a", stderr))
            {
                std::cerr << std::fixed << std::setprecision(__precision__);
            }
#endif
#ifdef stdout_path
            if(not freopen(stdout_path, "w", stdout))
            {
                freopen("CON", "w", stdout);
                std::cerr << "Failed to open the stdout file\n\n";
            }
            std::cout << "";
#endif
#ifdef stdin_path
            if(not freopen(stdin_path, "r", stdin))
            {
                freopen("CON", "r", stdin);
                std::cerr << "Failed to open the stdin file\n\n";
            }
#endif
#ifdef LOCAL
            std::cerr << "----- stderr at LOCAL -----\n\n";
            atexit(print_elapsed_time);
            start_time = std::chrono::system_clock::now();
#else
            fclose(stderr);
#endif
        }
    } __setupper;
} // namespace execution

class myclock_t
{
    std::chrono::system_clock::time_point built_pt, last_pt;
    int built_ln, last_ln;
    std::string built_func, last_func;
    bool is_built;

public:
    explicit myclock_t() : is_built(false)
    {
    }
    void build(int crt_ln, const std::string &crt_func)
    {
        is_built = true;
        last_pt = built_pt = std::chrono::system_clock::now();
        last_ln = built_ln = crt_ln, last_func = built_func = crt_func;
    }
    void set(int crt_ln, const std::string &crt_func)
    {
        if(is_built)
        {
            last_pt = std::chrono::system_clock::now();
            last_ln = crt_ln, last_func = crt_func;
        }
        else
        {
            debug_stream << "[ " << crt_ln << " : " << crt_func << " ] "
                        << "myclock_t::set failed (yet to be built!)\n";
        }
    }
    void get(int crt_ln, const std::string &crt_func)
    {
        if(is_built)
        {
            std::chrono::system_clock::time_point crt_pt(
                std::chrono::system_clock::now());
            int64_t diff =
                std::chrono::duration_cast<std::chrono::milliseconds>(crt_pt -
                                                                    last_pt)
                    .count();
            debug_stream << diff << " ms elapsed from"
                        << " [ " << last_ln << " : " << last_func << " ]";
            if(last_ln == built_ln) debug_stream << " (when built)";
            debug_stream << " to"
                        << " [ " << crt_ln << " : " << crt_func << " ]"
                        << "\n";
            last_pt = built_pt, last_ln = built_ln, last_func = built_func;
        }
        else
        {
            debug_stream << "[ " << crt_ln << " : " << crt_func << " ] "
                        << "myclock_t::get failed (yet to be built!)\n";
        }
    }
};
#ifdef LOCAL
myclock_t __myclock;
#define build_clock() __myclock.build(__LINE__, __func__)
#define set_clock() __myclock.set(__LINE__, __func__)
#define get_clock() __myclock.get(__LINE__, __func__)
#else
#define build_clock() ((void)0)
#define set_clock() ((void)0)
#define get_clock() ((void)0)
#endif

namespace std
{
    template <class RAitr>
    void rsort(RAitr __first, RAitr __last)
    {
        sort(__first, __last, greater<>());
    }
    template <class T>
    size_t hash_combine(size_t seed, T const &key)
    {
        return seed ^ (hash<T>()(key) + 0x9e3779b9 + (seed << 6) + (seed >> 2));
    }
    template <class T, class U>
    struct hash<pair<T, U>>
    {
        size_t operator()(pair<T, U> const &pr) const
        {
            return hash_combine(hash_combine(0, pr.first), pr.second);
        }
    };
    template <class tuple_t, size_t index = tuple_size<tuple_t>::value - 1>
    struct tuple_hash_calc
    {
        static size_t apply(size_t seed, tuple_t const &t)
        {
            return hash_combine(
                tuple_hash_calc<tuple_t, index - 1>::apply(seed, t),
                get<index>(t));
        }
    };
    template <class tuple_t>
    struct tuple_hash_calc<tuple_t, 0>
    {
        static size_t apply(size_t seed, tuple_t const &t)
        {
            return hash_combine(seed, get<0>(t));
        }
    };
    template <class... T>
    struct hash<tuple<T...>>
    {
        size_t operator()(tuple<T...> const &t) const
        {
            return tuple_hash_calc<tuple<T...>>::apply(0, t);
        }
    };
    template <class T, class U>
    istream &operator>>(std::istream &s, pair<T, U> &p)
    {
        return s >> p.first >> p.second;
    }
    template <class T, class U>
    ostream &operator<<(std::ostream &s, const pair<T, U> p)
    {
        return s << p.first << " " << p.second;
    }
    template <class T>
    istream &operator>>(istream &s, vector<T> &v)
    {
        for(T &e : v)
        {
            s >> e;
        }
        return s;
    }
    template <class T>
    ostream &operator<<(ostream &s, const vector<T> &v)
    {
        bool is_front = true;
        for(const T &e : v)
        {
            if(not is_front)
            {
                s << ' ';
            }
            else
            {
                is_front = false;
            }
            s << e;
        }
        return s;
    }
    template <class tuple_t, size_t index>
    struct tupleos
    {
        static ostream &apply(ostream &s, const tuple_t &t)
        {
            tupleos<tuple_t, index - 1>::apply(s, t);
            return s << " " << get<index>(t);
        }
    };
    template <class tuple_t>
    struct tupleos<tuple_t, 0>
    {
        static ostream &apply(ostream &s, const tuple_t &t)
        {
            return s << get<0>(t);
        }
    };
    template <class... T>
    ostream &operator<<(ostream &s, const tuple<T...> &t)
    {
        return tupleos<tuple<T...>, tuple_size<tuple<T...>>::value - 1>::apply(
            s, t);
    }
    template <>
    ostream &operator<<(ostream &s, const tuple<> &t)
    {
        return s;
    }
    string revstr(string str)
    {
        reverse(str.begin(), str.end());
        return str;
    }
} // namespace std

#ifdef LOCAL
#define dump(...)                                                              \
    debug_stream << "[ " << __LINE__ << " : " << __FUNCTION__ << " ]\n",       \
        dump_func(#__VA_ARGS__, __VA_ARGS__)
template <class T>
void dump_func(const char *ptr, const T &x)
{
    debug_stream << '\t';
    for(char c = *ptr; c != '\0'; c = *++ptr)
    {
        if(c != ' ') debug_stream << c;
    }
    debug_stream << " : " << x << '\n';
}
template <class T, class... rest_t>
void dump_func(const char *ptr, const T &x, rest_t... rest)
{
    debug_stream << '\t';
    for(char c = *ptr; c != ','; c = *++ptr)
    {
        if(c != ' ') debug_stream << c;
    }
    debug_stream << " : " << x << ",\n";
    dump_func(++ptr, rest...);
}
#else
#define dump(...) ((void)0)
#endif
template <class P>
void read_range(P __first, P __second)
{
    for(P i = __first; i != __second; ++i)
        std::cin >> *i;
}
template <class P>
void write_range(P __first, P __second)
{
    for(P i = __first; i != __second;
        std::cout << (++i == __second ? '\n' : ' '))
    {
        std::cout << *i;
    }
}

// substitute y for x.
template <class T>
void subst(T &x, const T &y)
{
    x = y;
}
// substitue y for x iff x > y.
template <class T>
bool chmin(T &x, const T &y)
{
    return x > y ? x = y, true : false;
}
// substitue y for x iff x < y.
template <class T>
bool chmax(T &x, const T &y)
{
    return x < y ? x = y, true : false;
}
template <class T>
constexpr T minf(const T &x, const T &y)
{
    return std::min(x, y);
}
template <class T>
constexpr T maxf(const T &x, const T &y)
{
    return std::max(x, y);
}
// binary search.
template <class int_t, class F>
int_t bin(int_t ok, int_t ng, const F &f)
{
    while(std::abs(ok - ng) > 1)
    {
        int_t mid = (ok + ng) / 2;
        (f(mid) ? ok : ng) = mid;
    }
    return ok;
}
// be careful that val is type-sensitive.
template <class T, class A, size_t N>
void init(A (&array)[N], const T &val)
{
    std::fill((T *)array, (T *)(array + N), val);
}
void reset()
{
}
template <class A, class... rest_t>
void reset(A &array, rest_t... rest)
{
    memset(array, 0, sizeof(array));
    reset(rest...);
}
// a integer uniformly and randomly chosen from the interval [l, r).
template <typename int_t>
int_t rand_int(int_t l, int_t r)
{
    static std::random_device seed_gen;
    static std::mt19937 engine(seed_gen());
    std::uniform_int_distribution<int_t> unid(l, r - 1);
    return unid(engine);
}
// a real number uniformly and randomly chosen from the interval [l, r).
template <typename real_t>
real_t rand_real(real_t l, real_t r)
{
    static std::random_device seed_gen;
    static std::mt19937 engine(seed_gen());
    std::uniform_real_distribution<real_t> unid(l, r);
    return unid(engine);
}

/* The main code follows. */

#ifndef modint_hpp
#define modint_hpp
#include <cassert>
#include <iostream>

template <int mod>
class modint
{
    int val;
public:
    constexpr long long value() const noexcept { return val; }
    constexpr modint() noexcept : val{0} {}
    constexpr modint(long long x) noexcept : val((x %= mod) < 0 ? mod + x : x) {}
    constexpr modint operator++(int) noexcept { modint t = *this; return ++val, t; }
    constexpr modint operator--(int) noexcept { modint t = *this; return --val, t; }
    constexpr modint &operator++() noexcept { return ++val, *this; }
    constexpr modint &operator--() noexcept { return --val, *this; }
    constexpr modint operator-() const noexcept { return modint(-val); }
    constexpr modint &operator+=(const modint &other) noexcept { return (val += other.val) < mod ? 0 : val -= mod, *this; }
    constexpr modint &operator-=(const modint &other) noexcept { return (val += mod - other.val) < mod ? 0 : val -= mod, *this; }
    constexpr modint &operator*=(const modint &other) noexcept { return val = (long long)val * other.val % mod, *this; }
    constexpr modint &operator/=(const modint &other) noexcept { return *this *= inverse(other); }
    constexpr modint operator+(const modint &other) const noexcept { return modint(*this) += other; }
    constexpr modint operator-(const modint &other) const noexcept { return modint(*this) -= other; }
    constexpr modint operator*(const modint &other) const noexcept { return modint(*this) *= other; }
    constexpr modint operator/(const modint &other) const noexcept { return modint(*this) /= other; }
    constexpr bool operator==(const modint &other) const noexcept { return val == other.val; }
    constexpr bool operator!=(const modint &other) const noexcept { return val != other.val; }
    constexpr bool operator!() const noexcept { return !val; }
    friend constexpr modint operator+(long long x, modint y) noexcept { return modint(x) + y; }
    friend constexpr modint operator-(long long x, modint y) noexcept { return modint(x) - y; }
    friend constexpr modint operator*(long long x, modint y) noexcept { return modint(x) * y; }
    friend constexpr modint operator/(long long x, modint y) noexcept { return modint(x) / y; }
    static constexpr modint inverse(const modint &other) noexcept
    {
        assert(other != 0);
        int a{mod}, b{other.val}, u{}, v{1}, t{};
        while(b) t = a / b, a ^= b ^= (a -= t * b) ^= b, u ^= v ^= (u -= t * v) ^= v;
        return {u};
    }
    static constexpr modint pow(modint other, long long e) noexcept
    {
        if(e < 0) e = e % (mod - 1) + mod - 1;
        modint res{1};
        while(e) { if(e & 1) res *= other; other *= other, e >>= 1; }
        return res;
    }
    friend std::ostream &operator<<(std::ostream &os, const modint &other) noexcept { return os << other.val; }
    friend std::istream &operator>>(std::istream &is, modint &other) noexcept { long long val; other = {(is >> val, val)}; return is; }
}; // class modint

#endif // modint_hpp

#ifndef binomial_hpp
#define binomial_hpp

namespace binomial
{
    constexpr int mod = //*
                        998244353
                        /*/
                        1000000007
                        /**/;
    constexpr int size = 1 << 19;
    using mint = modint<mod>;
    namespace
    {
        namespace internal_helper
        {
            struct fact_impl
            {
                int _fact[size], _inv[size], _invfact[size];
                fact_impl() : _fact{1}, _inv{0, 1}, _invfact{1}
                {
                    for(int i = 1; i < size; ++i) _fact[i] = (long long)_fact[i - 1] * i % mod;
                    for(int i = 2; i < size; ++i) _inv[i] = mod - (long long)mod / i * _inv[mod % i] % mod;
                    for(int i = 1; i < size; ++i) _invfact[i] = (long long)_invfact[i - 1] * _inv[i] % mod;
                }
            } fact_calced;
        } // namespace internal_helper
        mint fact(int x) noexcept { assert(x < size); return x < 0 ? 0 : internal_helper::fact_calced._fact[x]; }
        mint invfact(int x) noexcept { assert(x < size); return x < 0 ? 0 : internal_helper::fact_calced._invfact[x]; }
        mint inv(int x) noexcept { assert(x < size); return x < 0 ? 0 : internal_helper::fact_calced._inv[x]; }
    } // unnamed namespace
    mint binom(int n, int k) noexcept { return fact(n) * invfact(k) * invfact(n - k); }
    mint fallfact(int n, int k) noexcept { return fact(n) * invfact(n - k); }
    mint risefact(int n, int k) noexcept { return fallfact(n + k - 1, k); }
    // time complexity: O(min(n, k) * log(n))
    mint stirling_2nd(int n, int k) noexcept
    {
        if(n < k) return 0;
        mint res{};
        for(int i{}, j{k}; j >= 0; ++i, --j)
            if(i & 1) res -= mint::pow(j, n) * invfact(j) * invfact(i);
            else res += mint::pow(j, n) * invfact(j) * invfact(i);
        return res;
    };
    // time complexity: O(min(n, k) * log(n))
    mint bell(int n, int k) noexcept
    {
        if(n < k) k = n;
        mint res{}, alt{};
        for(int i{}, j{k}; j >= 0; ++i, --j)
        {
            if(i & 1) alt -= invfact(i);
            else alt += invfact(i);
            res += alt * mint::pow(j, n) * invfact(j);
        }
        return res;
    }
    namespace internal_helper {} // namespace internal_helper
} // namespace binomial

#endif // binomial_hpp

using namespace std;

signed main()
{
    void __solve();
    void __precalc();

    unsigned int t = 1;
    // cin >> t;
    // __precalc();

#ifdef LOCAL
    t = 3;
#endif

    while(t--)
    {
        __solve();
    }
}

using namespace binomial;



void __solve()
{
    int a, b, c;
    cin >> a >> b >> c;
    const int n=a+b+c;
    mint ans=0;
    mint po=mint::pow(mint(2),c);
    for(int i = c; i <= n-2; ++i,po*=2)
    {
        ans+=(po-1)*binom(i-1,c-1)*binom(i-c,b-1);
    }
    std::cout << ans << "\n";
}