#include <bits/stdc++.h>
using namespace std;
int inf = 1000000005;
long long int llinf = 2000000000000000005LL;
double PI = 3.1415926535897;
double eps = 1e-15;
int dx[] = {1, -1, 0, 0, 1, -1, 1, -1}, dy[] = {0, 0, 1, -1, 1, 1, -1, -1};
const int mxn = 5005, mod = 998244353;
long long int dp[mxn][mxn];
long long int solve(int a, int b) {
  if (a < b) swap(a, b);
  return dp[a][b];
}
int main() {
  for (int i = (0); i < (mxn); i++)
    for (int j = (0); j < (i + 1); j++) {
      if (i == 0 || j == 0)
        dp[i][j] = 1;
      else
        dp[i][j] = (i * dp[i - 1][j - 1] % mod + dp[i][j - 1]) % mod;
    }
  int a, b, c;
  cin >> a >> b >> c;
  cout << (solve(a, b) * solve(b, c) % mod) * solve(c, a) % mod << endl;
}
