#include <bits/stdc++.h>
using namespace std;
long long a, b, rsp, i, j, k, finans, aux1, aux2, fact[5005], v[5],
    c[5005][5005];
int main() {
  cin >> v[1] >> v[2] >> v[3];
  finans = 1LL;
  fact[0] = 1LL;
  for (i = 1; i <= 5000; i++) fact[i] = (fact[i - 1] * i) % 998244353;
  c[0][0] = 1LL;
  for (i = 1; i <= 5000; i++) {
    c[i][0] = c[i][i] = 1;
    for (j = 1; j < i; j++)
      c[i][j] = (c[i - 1][j] + c[i - 1][j - 1]) % 998244353;
  }
  for (i = 1; i <= 2; i++) {
    for (j = i + 1; j <= 3; j++) {
      a = min(v[i], v[j]);
      b = max(v[i], v[j]);
      rsp = 0;
      for (k = 0; k <= a; k++)
        rsp = (rsp + ((c[a][k] * c[b][k]) % 998244353) * fact[k]) % 998244353;
      finans = (finans * rsp) % 998244353;
    }
  }
  cout << finans;
}
