#include <bits/stdc++.h>
using namespace std;
const long long mod = 998244353;
const long long N = 5005;
long long fac[N];
long long C[5005][5005];
long long calc(long long x, long long y) {
  long long ret = 0;
  long long minn = min(x, y);
  for (long long i = 1; i <= minn; i++) {
    ret = (ret + C[x][i] * C[y][i] % mod * fac[i] % mod) % mod;
  }
  return ret;
}
signed main() {
  long long a, b, c;
  cin >> a >> b >> c;
  long long maxn = max(a, max(b, c));
  fac[1] = 1;
  for (long long i = 2; i <= maxn; i++) {
    fac[i] = (fac[i - 1] * i) % mod;
  }
  C[0][0] = 1;
  for (long long i = 1; i <= maxn; i++) {
    for (long long j = 0; j <= i; j++) {
      C[i][j] = (C[i - 1][j] + C[i - 1][j - 1]) % mod;
    }
  }
  cout << (calc(a, b) + 1) * (calc(b, c) + 1) % mod * (calc(c, a) + 1) % mod;
}
