#include <bits/stdc++.h>
using namespace std;
const int mod = 998244353;
int a, b, c, F[5001];
int Power(int n, int k) {
  if (k == 0) return 1;
  if (k == 1) return n % mod;
  int tmp = Power(n, k / 2);
  tmp = 1ll * tmp * tmp % mod;
  if (k % 2 == 0) return tmp;
  return 1ll * tmp * n % mod;
}
int P(int n, int m) { return 1ll * F[m] * Power(F[m - n], mod - 2) % mod; }
int C(int n, int m) {
  return 1ll * F[m] * Power(1ll * F[n] * F[m - n] % mod, mod - 2) % mod;
}
int Cal(int x, int y) {
  int n = min(x, y), m = max(x, y);
  int sum = 0;
  for (int d = 0; d <= n; d++) {
    int z = 1ll * C(d, n) * P(d, m) % mod;
    sum += z;
    sum %= mod;
  }
  return sum;
}
int main() {
  ios::sync_with_stdio(0);
  cin.tie(NULL);
  cout.tie(NULL);
  cin >> a >> b >> c;
  F[0] = 1;
  for (int i = 1; i <= 5000; i++) F[i] = 1ll * F[i - 1] * i % mod;
  cout << 1ll * Cal(a, b) * Cal(a, c) % mod * Cal(b, c) % mod;
  return 0;
}
