#include <bits/stdc++.h>
const int mod = 998244353;
const int N = 5003;
using namespace std;
long long C[N][N], a, b, c, mul[N];
long long solve(int A, int B) {
  long long now = 1;
  for (int i = 1; i <= A; ++i)
    now = (now + C[A][i] * C[B][i] % mod * mul[i] % mod) % mod;
  return now;
}
int main() {
  cin >> a >> b >> c;
  for (int i = 0; i <= 5000; ++i) C[i][0] = 1;
  for (int i = 1; i <= 5000; ++i)
    for (int j = 1; j <= i; ++j)
      C[i][j] = (C[i - 1][j - 1] + C[i - 1][j]) % mod;
  mul[0] = mul[1] = 1;
  for (int i = 1; i <= 5000; ++i) mul[i] = mul[i - 1] * i % mod;
  long long ans = 1;
  ans = ans * solve(a, b) % mod * solve(a, c) % mod * solve(b, c) % mod;
  cout << ans << endl;
  return 0;
}
