#include <bits/stdc++.h>
using namespace std;
const int MOD = 998244353;
int dp[5005][5005];
int ways(int a, int b) {
  if (a == 0 || b == 0) return 1;
  if (dp[a][b] == 0) {
    dp[a][b] = (b * 1ll * ways(a - 1, b - 1) + ways(a - 1, b)) % MOD;
  }
  return dp[a][b];
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  int a, b, c;
  cin >> a >> b >> c;
  if (a > b) swap(a, b);
  if (b > c) swap(b, c);
  if (a > b) swap(a, b);
  cout << (((ways(a, b) * 1ll * ways(b, c)) % MOD) * 1ll * ways(a, c)) % MOD
       << endl;
  return 0;
}
