#include <bits/stdc++.h>
using namespace std;
long long C[5001][5001], fak[5000], a, b, c, ans1, ans2, ans3;
const long long MOD = 998244353;
void generate() {
  C[0][0] = 1;
  for (long long i = 1; i <= 5000; i++) {
    C[i][0] = 1;
    for (long long j = 1; j <= i; j++) {
      C[i][j] = (C[i - 1][j] + C[i - 1][j - 1]) % MOD;
    }
  }
  fak[0] = 1;
  for (long long i = 1; i <= 5000; i++) {
    fak[i] = (fak[i - 1] * i) % MOD;
  }
}
int main() {
  generate();
  cin >> a >> b >> c;
  for (long long i = 0; i <= min(a, b); i++) {
    ans1 = (ans1 + ((C[a][i] * C[b][i]) % MOD * fak[i]) % MOD) % MOD;
  }
  for (long long i = 0; i <= min(b, c); i++) {
    ans2 = (ans2 + ((C[c][i] * C[b][i]) % MOD * fak[i]) % MOD) % MOD;
  }
  for (long long i = 0; i <= min(a, c); i++) {
    ans3 = (ans3 + ((C[a][i] * C[c][i]) % MOD * fak[i]) % MOD) % MOD;
  }
  cout << ((ans1 * ans2) % MOD * ans3) % MOD << "\n";
}
