#include <bits/stdc++.h>
using namespace std;
long long mod = 998244353;
long long p[5010][5010];
long long pre[5010];
long long calc(long long a, long long b) {
  long long ret = 0;
  for (int i = 0; i <= min(a, b); i++) {
    long long now = pre[i];
    now *= p[a][i];
    now %= mod;
    now *= p[b][i];
    now %= mod;
    ret += now;
    ret %= mod;
  }
  return ret % mod;
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  ;
  p[0][0] = 1;
  for (long long i = 1; i <= 5000; i++) {
    p[i][0] = 1;
    for (long long j = 1; j <= i; j++) {
      p[i][j] = p[i - 1][j] + p[i - 1][j - 1];
      p[i][j] %= mod;
    }
  }
  pre[0] = 1;
  for (long long i = 1; i <= 5000; i++) {
    pre[i] = pre[i - 1] * i;
    pre[i] %= mod;
  }
  long long ans = 1;
  long long a, b, c;
  cin >> a >> b >> c;
  ans *= calc(a, b);
  ans %= mod;
  ans *= calc(b, c);
  ans %= mod;
  ans *= calc(a, c);
  ans %= mod;
  cout << ans << endl;
  return 0;
}
