#include <bits/stdc++.h>
using namespace std;
const int mod = 998244353;
int dp[5005][5005];
int fact[5005];
int solve(int a, int b) {
  int ret = 0;
  for (int i = 0; i <= min(a, b); i++) {
    ret =
        (ret + ((((1ll * dp[a][i]) * dp[b][i]) % mod) * (fact[i])) % mod) % mod;
  }
  return ret;
}
int main() {
  int a, b, c;
  cin >> a >> b >> c;
  for (int i = 0; i <= 5000; i++) {
    for (int j = 0; j <= i; j++) {
      if (i == 1 || i == 0 || j == 0) {
        dp[i][j] = 1;
        continue;
      }
      dp[i][j] = (dp[i - 1][j - 1] + dp[i - 1][j]) % mod;
    }
  }
  fact[0] = 1;
  for (int i = 1; i <= 5000; i++) {
    fact[i] = (1ll * fact[i - 1] * i) % mod;
  }
  cout << ((((1ll * solve(a, b)) * solve(b, c)) % mod) * solve(a, c)) % mod;
}
