#include <bits/stdc++.h>
using namespace std;
const long long mod = 998244353;
const int maxn = 5005;
long long CHS[maxn][maxn];
long long Fact[maxn];
long long solve(int a, int b) {
  long long ans = 0;
  for (int e = 0; e <= min(a, b); ++e) {
    long long res = 1;
    res = (res * CHS[a][e]) % mod;
    res = (res * CHS[b][e]) % mod;
    res = (res * Fact[e]) % mod;
    ans = (ans + res) % mod;
  }
  return ans;
}
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  Fact[0] = 1;
  for (long long x = 1; x < maxn; ++x) {
    Fact[x] = (Fact[x - 1] * x) % mod;
  }
  for (int i = 0; i < maxn; ++i) {
    CHS[i][0] = CHS[i][i] = 1;
    for (int j = i + 1; j < maxn; ++j) {
      CHS[i][j] = 0;
    }
    if (i > 0) {
      for (int j = 1; j < i; ++j) {
        CHS[i][j] = (CHS[i - 1][j - 1] + CHS[i - 1][j]) % mod;
      }
    }
  }
  int a[3] = {};
  for (int i = 0; i < 3; ++i) {
    cin >> a[i];
  }
  long long ans = 1;
  for (int i = 0; i < 3; ++i) {
    for (int j = i + 1; j < 3; ++j) {
      ans = (ans * solve(a[i], a[j])) % mod;
    }
  }
  cout << ans << '\n';
}
