#include <bits/stdc++.h>
using namespace std;
long long k[5005];
int cc[5002][5002];
long long cal(long long a, long long b) {
  long long sum = 1;
  for (int i = 1; i <= min(a, b); i++) {
    sum += ((long long)(cc[a][i]) * (long long)(cc[b][i]) % 998244353) * k[i];
    sum %= 998244353;
  }
  return sum;
}
int main() {
  long long a, b, c;
  cin >> a >> b >> c;
  long long ans = 1;
  k[0] = 1;
  k[1] = 1;
  for (long long i = 2; i <= 5000; i++) k[i] = (k[i - 1] * i) % 998244353;
  for (long long i = 0; i <= 5000; i++) cc[i][0] = 1;
  for (int i = 1; i <= 5000; i++)
    for (int j = 1; j <= i; j++)
      cc[i][j] = (cc[i - 1][j - 1] + cc[i - 1][j]) % 998244353;
  long long aa = cal(a, b);
  long long bb = cal(b, c);
  long long cc = cal(a, c);
  ans = (aa * bb % 998244353) * cc % 998244353;
  printf("%lld", ans);
}
