#include <bits/stdc++.h>
using namespace std;
const double PI = acos(-1.0);
const int INF = 1000 * 1000 * 1000 + 7;
const long long LINF = INF * (long long)INF;
const int L = 20;
const int MAX = 5000 + 47;
const int MOD = 998244353;
long long C[MAX][MAX];
long long F[MAX];
void precalc() {
  C[0][0] = 1;
  for (int i = (1); i < (MAX); i++) {
    C[i][0] = 1;
    for (int j = (1); j < (i + 1); j++) {
      C[i][j] = C[i - 1][j - 1] + C[i - 1][j];
      if (C[i][j] >= MOD) C[i][j] -= MOD;
    }
  }
  F[0] = 1;
  for (int i = (1); i < (MAX); i++) F[i] = (F[i - 1] * i) % MOD;
}
long long calc(int a, int b) {
  long long ans = 0;
  for (int k = (0); k < (min(a, b) + 1); k++) {
    long long tmp = (C[a][k] * C[b][k]) % MOD;
    ans = (ans + tmp * F[k]) % MOD;
  }
  return ans;
}
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int a, b, c;
  precalc();
  cin >> a >> b >> c;
  long long ans = (calc(a, b) * calc(b, c)) % MOD;
  ans = (ans * calc(c, a)) % MOD;
  cout << ans << endl;
}
