#include <bits/stdc++.h>
using namespace std;
const long long MOD = 998244353LL;
const int maxn = 5 * 1e3 + 17;
long long a, b, c;
long long fact[maxn];
long long nCk[maxn][maxn];
void add(long long &x, long long y) {
  if (y >= MOD) y %= MOD;
  x += y;
  if (x >= MOD) x %= MOD;
}
void mult(long long &x, long long y) {
  if (y >= MOD) y %= MOD;
  x *= y;
  if (x >= MOD) x %= MOD;
}
long long calc(long long x, long long y) {
  long long ret = 0;
  for (int i = 0; i <= min(x, y); i++)
    add(ret, (nCk[x][i] * nCk[y][i]) % MOD * fact[i]);
  return ret;
}
int main() {
  fact[0] = 1LL;
  for (int i = 1; i < maxn; i++) fact[i] = 1LL * i * fact[i - 1] % MOD;
  for (int i = 0; i < maxn; i++) nCk[i][0] = 1LL, nCk[i][i] = 1LL;
  for (int i = 1; i < maxn; i++)
    for (int j = 1; j < maxn; j++)
      nCk[i][j] = (nCk[i - 1][j - 1] + nCk[i - 1][j]) % MOD;
  long long ret = 1LL;
  cin >> a >> b >> c;
  mult(ret, calc(a, b));
  mult(ret, calc(a, c));
  mult(ret, calc(b, c));
  cout << ret << endl;
  return 0;
}
