#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ii = pair<int, int>;
using pll = pair<ll, ll>;
using pdd = pair<double, double>;
using vi = vector<int>;
using vii = vector<ii>;
using vs = vector<string>;
const double PI = acos(-1.0);
const double EPS = 1e-14;
const int MOD = 998244353;
const int INF = 1e9;
const ll INFLL = 4e18;
const int MAX = 5e3;
ll A, B, C, ans = 1;
int memo[MAX + 5][MAX + 5];
void read() { cin >> A >> B >> C; }
ll calc(int x, int y) {
  if (x == 0 || y == 0) return 1;
  int &ret = memo[x][y];
  if (ret == -1) {
    ret = calc(x - 1, y) + (y * calc(x - 1, y - 1)) % MOD;
    ret %= MOD;
  }
  return ret;
}
void solve() {
  memset(memo, -1, sizeof memo);
  ans = calc(A, B);
  ans = (ans * calc(B, C)) % MOD;
  ans = (ans * calc(A, C)) % MOD;
  cout << ans << "\n";
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  int TC = 1;
  while (TC--) {
    read();
    solve();
  }
}
