#include <bits/stdc++.h>
using namespace std;
const int N = 5000 + 5;
const int mod = 998244353;
long long fac[N], C[N][N];
long long get(long long a, long long b) {
  if (a > b) swap(a, b);
  long long ans = 0, tmp = 0;
  for (int i = 0; i <= a; ++i) {
    tmp = C[a][i] * C[b][i] % mod * fac[i];
    ans = (ans + tmp) % mod;
  }
  return ans;
}
int main() {
  fac[0] = C[0][0] = 1;
  for (int i = 1; i <= 5000; ++i) fac[i] = fac[i - 1] * i % mod;
  for (int i = 1; i <= 5000; ++i) {
    C[i][0] = 1;
    C[i][i] = 1;
    for (int j = 1; j < i; ++j) {
      C[i][j] = C[i - 1][j - 1] + C[i - 1][j];
      C[i][j] %= mod;
    }
  }
  long long a, b, c;
  scanf("%lld%lld%lld", &a, &b, &c);
  long long ans = get(a, b);
  ans *= get(a, c);
  ans %= mod;
  ans *= get(b, c);
  ans %= mod;
  printf("%lld\n", ans);
}
