#include <bits/stdc++.h>
using namespace std;
const long long MD = 998244353;
const int MX = 5000 + 10;
vector<vector<long long>> dp(MX, vector<long long>(MX));
void populate() {
  dp[1][1] = 2;
  for (int i = 2; i < MX; i++) {
    dp[1][i] = dp[1][i - 1] + 1;
    dp[i][1] = dp[i - 1][1] + 1;
  }
  for (int i = 2; i < MX; i++) {
    for (int j = 2; j < MX; j++) {
      dp[i][j] = (dp[i - 1][j - 1] * i) % MD + (dp[i][j - 1]) % MD;
      dp[i][j] %= MD;
    }
  }
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  populate();
  int a, b, c;
  cin >> a >> b >> c;
  long long result = (dp[a][b] * dp[a][c]) % MD;
  result = (result * dp[b][c]) % MD;
  cout << result;
}
