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