#include <bits/stdc++.h>
using namespace std;
const int mod = 998244353;
int x, y, z;
long long ansx, ansy, ansz, ans, fac[5005], ine[5005];
long long qpow(int a, int b) {
  long long res = 1, base = a;
  while (b) {
    if (b & 1) res = 1ll * res * base % mod;
    base = 1ll * base * base % mod;
    b >>= 1;
  }
  return res;
}
long long C(int n, int m) {
  return 1ll * fac[n] * ine[n - m] % mod * ine[m] % mod;
}
long long A(int n, int m) { return 1ll * fac[n] * ine[n - m] % mod; }
int main() {
  scanf("%d%d%d", &x, &y, &z);
  fac[0] = 1;
  ine[0] = 1;
  for (int i = 1; i <= 5005; i++) {
    fac[i] = 1ll * fac[i - 1] * i % mod;
    ine[i] = qpow(fac[i], mod - 2);
  }
  for (int i = 0; i <= min(x, y); i++) {
    ansx = (ansx + 1ll * C(x, i) * A(y, i) % mod) % mod;
  }
  for (int i = 0; i <= min(z, y); i++) {
    ansy = (ansy + 1ll * C(y, i) * A(z, i) % mod) % mod;
  }
  for (int i = 0; i <= min(x, z); i++) {
    ansz = (ansz + 1ll * C(z, i) * A(x, i) % mod) % mod;
  }
  ans = 1ll * ansx * ansy % mod * ansz % mod;
  printf("%lld\n", ans);
}
