#include <bits/stdc++.h>
using namespace std;
long long dp[5005][5005];
long long solve(long long x, long long y) {
  if (x == 0 || y == 0) return 1;
  if (dp[x][y] == 0)
    dp[x][y] = (solve(x - 1, y - 1) * y + solve(x - 1, y)) % 998244353;
  return dp[x][y];
}
int main() {
  long long n, m, k;
  while (scanf("%lld%lld%lld", &n, &m, &k) != EOF) {
    memset(dp, 0, sizeof(0));
    printf("%lld\n",
           (solve(n, m) * solve(m, k) % 998244353) * solve(k, n) % 998244353);
  }
  return 0;
}
