#include <bits/stdc++.h>
using namespace std;
const long long mod = 998244353;
long long dp[5005][5005];
int main() {
  int a, b, c;
  cin >> a >> b >> c;
  for (int i = 1; i <= 5000; i++) dp[1][i] = dp[i][1] = i + 1;
  for (int i = 2; i <= 5000; i++)
    for (int j = 2; j <= 5000; j++)
      dp[i][j] = (j * dp[i - 1][j - 1] + dp[i - 1][j]) % mod;
  cout << (dp[a][b] * dp[b][c] % mod * dp[c][a]) % mod;
  return 0;
}
