#include <bits/stdc++.h>
using namespace std;
const long long mod = 998244353;
;
long long a, b, c;
long long fact[5001];
long long ans = 1;
long long comb[5001][5001];
long long f(long long a, long long b) {
  long long r = 1;
  int k = min(a, b);
  for (int i = 1; i <= k; i++)
    r = (r + ((((comb[a][i] * comb[b][i]) % mod) * fact[i]) % mod)) % mod;
  return r;
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  fact[0] = 1;
  for (int i = 1; i <= 5000; i++) {
    fact[i] = (fact[i - 1] * i) % mod;
  }
  comb[0][0] = 1;
  for (int i = 1; i <= 5000; i++) {
    comb[i][0] = 1;
    for (int j = 1; j <= i; j++) {
      comb[i][j] = (comb[i - 1][j] + comb[i - 1][j - 1]) % mod;
    }
  }
  cin >> a >> b >> c;
  ans = f(a, b);
  ans = (ans * f(b, c)) % mod;
  ans = (ans * f(c, a)) % mod;
  cout << ans << endl;
  return 0;
}
