#include <bits/stdc++.h>
using namespace std;
const int mod = 998244353;
int egcd(int a, int b, int& x, int& y) {
  if (b == 0) {
    x = 1;
    y = 0;
    return a;
  }
  int x1, y1, g = egcd(b, a % b, x1, y1);
  x = y1, y = x1 - y1 * (a / b);
  return g;
}
int inv[5001];
void initinv() {
  inv[0] = -1, inv[1] = 1;
  for (int i = 2; i < 5001; ++i)
    inv[i] = (long long)(mod - mod / i) * inv[mod % i] % mod;
}
int solve(int a, int b) {
  long long res = 0, t = 1;
  for (int i = 0; i <= min(a, b); ++i) {
    res += t;
    res %= mod;
    t *= a - i;
    t %= mod;
    t *= b - i;
    t %= mod;
    t *= inv[i + 1];
    t %= mod;
  }
  return (int)res;
}
int main() {
  int a, b, c;
  cin >> a >> b >> c;
  long long res = 1;
  initinv();
  res *= solve(a, b);
  res %= mod;
  res *= solve(a, c);
  res %= mod;
  res *= solve(b, c);
  res %= mod;
  cout << res << endl;
}
