#include <bits/stdc++.h>
using namespace std;
long long dp[5011][5011];
void fu() {
  for (long long i = 0; i <= 5001; i++) {
    for (long long j = 0; j <= 5001; j++) {
      if (i == 0) {
        dp[i][j] = 1;
      } else {
        dp[i][j] = (dp[i - 1][j]) % 998244353;
        if (j - 1 >= 0) {
          dp[i][j] =
              (dp[i][j] + ((long long)j * (dp[i - 1][j - 1])) % 998244353) %
              998244353;
        }
      }
    }
  }
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  memset(dp, 0, sizeof(dp));
  fu();
  long long a, b, c;
  cin >> a >> b >> c;
  long long an = dp[a][b];
  an = (an * dp[b][c]) % 998244353;
  an = (an * dp[c][a]) % 998244353;
  cout << an << endl;
}
