#include <bits/stdc++.h>
using namespace std;
int state[5005][5005];
inline int add(int a, int b) {
  a += b;
  if (a >= 998244353) {
    a -= 998244353;
  }
  return a;
}
inline int mult(int a, int b) { return (1LL * a * b) % 998244353; }
int dp(int a, int b) {
  if (a == 0 || b == 0) return 1;
  int &ans = state[a][b];
  if (ans != -1) return ans;
  ans = 0;
  ans = add(dp(a - 1, b), mult(dp(a - 1, b - 1), b));
  return ans;
}
int main() {
  ios_base::sync_with_stdio(false);
  long long a, b, c;
  cin >> a >> b >> c;
  memset(state, -1, sizeof state);
  int ans = mult(dp(a, b), mult(dp(a, c), dp(b, c)));
  cout << ans << endl;
  return 0;
}
