#include <bits/stdc++.h>
using namespace std;
const int mod = 998244353;
const int size = 5005;
int c[size][size], fact[size];
int solve(int a, int b) {
  long int res = 0;
  for (int i = 0; i <= a && i <= b; i++) {
    int ans = fact[i];
    ans = (1LL * c[a][i] * ans) % mod;
    ans = (1LL * c[b][i] * ans) % mod;
    res = (res + ans) % mod;
  }
  return res;
}
int main() {
  int r, b, p;
  cin >> r >> b >> p;
  memset(c, 0, sizeof(c));
  c[0][0] = 1;
  for (int i = 1; i <= 5000; i++) {
    c[i][0] = 1;
    for (int j = 1; j <= i; j++)
      c[i][j] = (c[i - 1][j - 1] % mod + c[i - 1][j] % mod) % mod;
  }
  memset(fact, 0, sizeof(fact));
  fact[0] = 1;
  for (int i = 1; i <= 5000; i++) fact[i] = (1LL * fact[i - 1] * i) % mod;
  long long int ans = 1;
  ans = (1LL * ans * solve(r, b)) % mod;
  ans = (1LL * ans * solve(b, p)) % mod;
  ans = (1LL * ans * solve(r, p)) % mod;
  cout << ans << "\n";
  return 0;
}
