#include <bits/stdc++.h>
const int maxn = 5e3 + 10;
using namespace std;
const int mod = 998244353;
long long fac[maxn];
long long C[maxn][maxn];
long long calc(long long a, long long b) {
  if (!(a < b)) {
    long long tmp = a;
    a = b;
    b = tmp;
  }
  long long ans = 0;
  long long tmp = 0;
  for (int i = 0; i <= a; i++) {
    tmp = C[a][i] * C[b][i];
    tmp %= mod;
    tmp *= fac[i];
    ans += tmp;
    ans %= mod;
  }
  return ans;
}
void init() {
  fac[0] = C[0][0] = 1;
  for (int i = 1; i < maxn; i++) fac[i] = fac[i - 1] * i % mod;
  for (int i = 1; i < maxn; 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, CC;
int main() {
  init();
  scanf("%lld%lld%lld", &A, &B, &CC);
  long long ans = calc(A, B);
  ans %= mod;
  ans *= calc(A, CC) % mod;
  ans %= mod;
  ans *= calc(B, CC) % mod;
  printf("%lld\n", ans % mod);
}
