#include <bits/stdc++.h>
using namespace std;
const int n = 5000;
const long long mod = 998244353;
long long f[n + 10][n + 10];
int main() {
  int a, b, c;
  for (int i = 1; i < n + 10; i++) {
    for (int j = 1; j < n + 10; j++) {
      if (i == 1)
        f[i][j] = j + 1;
      else if (j < i)
        f[i][j] = f[j][i];
      else {
        (f[i][j] += j * f[i - 1][j - 1] % mod) %= mod;
        (f[i][j] += f[i - 1][j]) %= mod;
      }
    }
  }
  while (scanf("%d%d%d", &a, &b, &c) != EOF) {
    long long ans = ((f[a][b] * f[b][c]) % mod) * f[c][a] % mod;
    printf("%lld\n", ans);
  }
  return 0;
}
