#include <bits/stdc++.h>
using namespace std;
const int mod = 998244353;
const int inf = 0x3c3c3c3c;
const long long infl = 0x3c3c3c3c3c3c3c3c;
long long dp[5003][5003];
int A, B, C;
int main() {
  ios::sync_with_stdio(0), cin.tie(0);
  ;
  cin >> A >> B >> C;
  vector<int> v({A, B, C});
  sort((v).begin(), (v).end());
  for (int i = 0; i <= 5000; i++) dp[i][0] = 1;
  for (int i = 1; i <= 5000; i++) {
    for (int j = 1; j <= 5000; j++) {
      dp[i][j] = (dp[i - 1][j - 1] * i + dp[i][j - 1]) % mod;
    }
  }
  long long ans = 1;
  ans = (ans * dp[v[2]][v[1]]) % mod;
  ans = (ans * dp[v[2]][v[0]]) % mod;
  ans = (ans * dp[v[1]][v[0]]) % mod;
  cout << ans;
}
