#include <bits/stdc++.h>
using namespace std;
const int mod = 998244353;
int a, b, c, dp[5023][5023];
int main() {
  cin >> a >> b >> c;
  if (a < b) swap(a, b);
  if (a < c) swap(a, c);
  if (b < c) swap(b, c);
  dp[0][0] = 1;
  for (int j, i = 1; i <= a; ++i) {
    dp[i][0] = 1;
    for (j = 1; j <= i; ++j)
      dp[i][j] = (dp[i][j - 1] + (long long)i * dp[i - 1][j - 1] % mod) % mod;
  }
  long long ans = dp[a][b];
  ans = ans * dp[a][c] % mod;
  ans = ans * dp[b][c] % mod;
  cout << ans;
  return 0;
}
