#include <bits/stdc++.h>
using namespace std;
int a, b, c;
long long bin[5010][5020], f[5010];
long long mulmod(long long a, long long b, long long mod = 998244353) {
  long long res = 0;
  a = a % mod;
  while (b > 0) {
    if (b % 2 == 1) res = (res + a) % mod;
    a = (a * 2) % mod;
    b /= 2;
  }
  return res % mod;
}
void binomial() {
  memset(bin, 0, sizeof bin);
  for (int i = 0; i < (5010); ++i)
    for (int j = 0; j < (min(5010, i) + 1); ++j) {
      if (j == 0 || j == i)
        bin[i][j] = 1;
      else
        bin[i][j] = (bin[i - 1][j - 1] + bin[i - 1][j]) % 998244353;
    }
  f[0] = 1;
  for (int i = (1); i <= (5010); ++i) f[i] = mulmod(f[i - 1], i);
}
long long solve(int a, int b) {
  long long res = 0;
  for (int i = 0; i < (min(a, b) + 1); ++i) {
    if (i == 0)
      res = (res + 1) % 998244353;
    else
      res = (res + mulmod(mulmod(bin[a][i], bin[b][i]), f[i])) % 998244353;
  }
  return res;
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  cin >> a >> b >> c;
  long long res, res1, res2, res3;
  binomial();
  res1 = solve(a, b);
  res2 = solve(a, c);
  res3 = solve(b, c);
  res = mulmod(mulmod(res1, res2), res3);
  cout << res;
  return 0;
}
