#include <bits/stdc++.h>
using namespace std;
int p[5007][5007];
int fact[5007];
int a, b, c;
void boost() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
}
int fun(int x, int y) {
  int r = 0;
  for (int i = 0; i <= x && i <= y; i++) {
    int d = fact[i];
    d = (1LL * d * p[x][i]) % 998244353;
    d = (1LL * d * p[y][i]) % 998244353;
    r = (r + d) % 998244353;
  }
  return r;
}
int main() {
  boost();
  cin >> a >> b >> c;
  memset(p, 0, sizeof(p));
  p[0][0] = 1;
  for (int i = 1; i <= 5000; i++) {
    p[i][0] = 1;
    for (int j = 1; j <= i; j++) {
      p[i][j] = (p[i - 1][j - 1] + p[i - 1][j]) % 998244353;
    }
  }
  memset(fact, 0, sizeof(fact));
  fact[0] = 1;
  for (int i = 1; i <= 5000; i++) fact[i] = (1LL * fact[i - 1] * i) % 998244353;
  int ans = 1;
  ans = (1LL * ans * fun(a, b)) % 998244353;
  ans = (1LL * ans * fun(b, c)) % 998244353;
  ans = (1LL * ans * fun(c, a)) % 998244353;
  cout << ans << endl;
  return 0;
}
