#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
const int mxn = 5e3 + 10;
const int mod = 998244353;
const int inf = 1e9;
ll dp[mxn][mxn];
ll calc(ll a, ll b) {
  if (dp[a][b] != -1) return dp[a][b];
  if (a == 1) return dp[a][b] = b + 1;
  if (b == 1) return dp[a][b] = a + 1;
  return dp[a][b] = (b * calc(a - 1, b - 1) % mod + calc(a - 1, b)) % mod;
}
signed main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  for (int i = 0; i < mxn; i++)
    for (int j = 0; j < mxn; j++) dp[i][j] = -1;
  ll a, b, c;
  cin >> a >> b >> c;
  ll tmp1 = calc(a, b);
  ll tmp2 = calc(b, c);
  ll tmp3 = calc(c, a);
  ll ans = tmp1 * tmp2 % mod * tmp3 % mod;
  cout << ans << '\n';
  return 0;
}
