#include <bits/stdc++.h>
const long long mod = 998244353;
long long C[5005][5005] = {0}, P[5005];
int main() {
  C[0][0] = 1;
  for (int i = 1; i <= 5000; i++) {
    C[i][0] = 1;
    for (int j = 1; j <= i; j++)
      C[i][j] = (C[i - 1][j] + C[i - 1][j - 1]) % mod;
  }
  P[0] = 1;
  P[1] = 1;
  for (int i = 2; i <= 5000; i++) P[i] = P[i - 1] * i % mod;
  long long a, b, c;
  scanf("%lld%lld%lld", &a, &b, &c);
  long long tmp1 = 0;
  for (int i = 0; i <= a; i++) {
    tmp1 = (tmp1 + C[a][i] * C[b][i] % mod * P[i] % mod) % mod;
  }
  long long tmp2 = 0;
  for (int k = 0; k <= b; k++) {
    tmp2 = (tmp2 + C[b][k] * C[c][k] % mod * P[k] % mod) % mod;
  }
  long long tmp3 = 0;
  for (int j = 0; j <= c; j++) {
    tmp3 = (tmp3 + C[c][j] * C[a][j] % mod * P[j] % mod) % mod;
  }
  long long ans = tmp1 * tmp2 % mod * tmp3 % mod;
  printf("%lld\n", ans);
  return 0;
}
