#include <bits/stdc++.h>
using namespace std;
void JIZZ() {
  cout << "";
  exit(0);
}
const long double PI = 3.14159265358979323846264338327950288;
const long double eps = 1e-13;
const long long mod = 998244353;
long long c[5555][5555];
void initc() {
  c[0][0] = 1;
  for (int i = 1; i < 5555; ++i) {
    for (int j = 0; j <= i; ++j) {
      c[i][j] += c[i - 1][j];
      if (j) c[i][j] += c[i - 1][j - 1];
      c[i][j] %= mod;
    }
  }
}
long long meow(long long a, long long b) {
  long long ans = 0;
  for (long long tra = 0; tra <= a; ++tra) {
    if (a - tra > b) continue;
    long long cur = 1;
    cur = cur * c[a][tra] % mod;
    for (long long i = b, j = 0; j < a - tra; ++j, --i) cur = cur * i % mod;
    ans = ans + cur;
    ans %= mod;
    ;
    ;
  };
  ;
  return ans;
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  initc();
  long long a, b, c;
  cin >> a >> b >> c;
  long long ans = 1;
  ans = ans * meow(a, b) % mod;
  ans = ans * meow(b, c) % mod;
  ans = ans * meow(c, a) % mod;
  cout << ans << endl;
}
