#include <bits/stdc++.h>
using namespace std;
const int inf = 1e9 + 7;
template <class T>
void dbs(string str, T t) {
  cout << str << " : " << t << endl;
}
template <class T, class... second>
void dbs(string str, T t, second... s) {
  int idx = str.find(',');
  cout << str.substr(0, idx) << " : " << t << ",";
  dbs(str.substr(idx + 1), s...);
}
template <class second, class T>
ostream& operator<<(ostream& os, const pair<second, T>& p) {
  return os << "(" << p.first << ", " << p.second << ")";
}
template <class T>
ostream& operator<<(ostream& os, const vector<T>& p) {
  os << "[ ";
  for (auto& it : p) os << it << " ";
  return os << "]";
}
template <class T>
ostream& operator<<(ostream& os, const set<T>& p) {
  os << "[ ";
  for (auto& it : p) os << it << " ";
  return os << "]";
}
template <class second, class T>
ostream& operator<<(ostream& os, const map<second, T>& p) {
  os << "[ ";
  for (auto& it : p) os << it << " ";
  return os << "]";
}
template <class T>
void prc(T a, T b) {
  cout << "[";
  for (T i = a; i != b; ++i) {
    if (i != a) cout << ", ";
    cout << *i;
  }
  cout << "]";
  cout << endl;
}
const int mod = 998244353;
int C[5001][5001];
long long f(int a, int b) {
  if (a > b) swap(a, b);
  long long ans = 0;
  long long fac = 1;
  for (int i = (0); i <= (a); ++i) {
    ans += ((C[a][i] * 1LL * C[b][i]) % mod) * 1LL * fac;
    ans %= mod;
    fac = (fac * (i + 1)) % mod;
  }
  return ans;
}
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  for (int i = (0); i <= (5000); ++i) {
    C[i][0] = 1;
    for (int j = (1); j <= (i); ++j) {
      C[i][j] = C[i - 1][j - 1] + C[i - 1][j];
      if (C[i][j] >= mod) C[i][j] -= mod;
    }
  }
  int a, b, c;
  cin >> a >> b >> c;
  long long ans = 1;
  ans *= f(a, b), ans %= mod;
  ans *= f(c, b), ans %= mod;
  ans *= f(a, c), ans %= mod;
  cout << ans;
  return 0;
}
