#include <bits/stdc++.h>
using namespace std;
long long m[5009][5009];
long long ch(long long n, long long k) {
  if (n < k) {
    long long t = n;
    n = k;
    k = t;
  }
  for (int i = 0; i <= n; i++) {
    m[0][i] = m[i][0] = 1;
  }
  for (int i = 1; i <= n; i++) {
    for (int j = 1; j <= k && j <= i; j++) {
      if (i == j)
        m[i][j] = (m[i - 1][j - 1] * j + m[i][j - 1]) % 998244353;
      else
        m[i][j] = (m[i - 1][j - 1] * j + m[i - 1][j]) % 998244353;
    }
  }
  return m[n][k];
}
int main() {
  int a, b, c;
  cin >> a >> b >> c;
  cout << (((ch(a, b) * ch(b, c)) % 998244353) * ch(a, c)) % 998244353 << endl;
  return 0;
}
