#include <bits/stdc++.h>
using namespace std;
int a, b, c, ans;
int fc[5005 + 5], rfc[5005 + 5], ri[5005 + 5];
void init() {
  fc[0] = fc[1] = rfc[0] = rfc[1] = 1;
  ri[1] = 1;
  for (int i = 2; i < 5005; i++) {
    int q = 998244353 / i, r = 998244353 % i;
    ri[i] = 1ll * (998244353 - q) * ri[r] % 998244353;
    fc[i] = 1ll * fc[i - 1] * i % 998244353;
    rfc[i] = 1ll * rfc[i - 1] * ri[i] % 998244353;
  }
}
int C(int n, int k) {
  if (k < 0 || k > n) return 0;
  if (k == 0 || k == n) return 1;
  return 1ll * (1ll * fc[n] * rfc[k] % 998244353) * rfc[n - k] % 998244353;
}
void calc(int a, int b) {
  if (a > b) swap(a, b);
  int rtn = 0;
  for (int i = 0; i <= a; i++) {
    (rtn += 1ll * C(a, i) * fc[b] % 998244353 * rfc[b - i] % 998244353) %=
        998244353;
  }
  ans = 1ll * rtn * ans % 998244353;
}
int main() {
  init();
  scanf("%d %d %d", &a, &b, &c);
  ans = 1;
  calc(a, b);
  calc(a, c);
  calc(c, b);
  printf("%d\n", ans);
}
