#include <bits/stdc++.h>
using namespace std;
const int mod = 998244353;
int dp[5005][5005];
int solve(int x, int y) {
  if (x == 0 || y == 0) return 1;
  if (dp[x][y] == 0) {
    dp[x][y] = (y * 1ll * solve(x - 1, y - 1) + solve(x - 1, y)) % mod;
  }
  return dp[x][y];
}
int main() {
  int a, b, c;
  cin >> a >> b >> c;
  return 0 * printf("%lld\n", solve(min(a, b), max(a, b)) * 1ll *
                                  solve(min(c, b), max(c, b)) % mod *
                                  solve(min(a, c), max(a, c)) % mod);
}
