#include <bits/stdc++.h>
using namespace std;
long long int fac[5001], perm[5001][5001];
int main() {
  long long int a, b, c;
  cin >> a >> b >> c;
  long long int mod = 998244353;
  fac[0] = 1;
  for (int i = 1; i < 5001; i++) {
    fac[i] = (fac[i - 1] * i) % mod;
  }
  perm[0][0] = 1;
  for (int i = 1; i < 5001; i++) {
    perm[i][0] = 1;
    for (int j = 1; j <= i; j++) {
      perm[i][j] = (perm[i - 1][j - 1] + perm[i - 1][j]) % mod;
    }
  }
  long long int ans = 1;
  for (int i = 0; i < 3; i++) {
    long long int t, u, v;
    if (i == 0) {
      t = min(a, b);
      u = a;
      v = b;
    }
    if (i == 1) {
      t = min(b, c);
      u = b;
      v = c;
    }
    if (i == 2) {
      t = min(a, c);
      u = a;
      v = c;
    }
    long long int sum = 0;
    for (int k = 0; k <= t; k++) {
      sum = (sum + ((perm[u][k] * perm[v][k]) % mod * fac[k]) % mod) % mod;
    }
    ans = (ans * sum) % mod;
  }
  cout << ans << endl;
  return 0;
}
