#include <bits/stdc++.h>
using namespace std;
long long x, y, z, f[5010][5010], lsg, n, xx, yy, zz;
signed main() {
  cin >> x >> y >> z;
  n = max(x, max(y, z));
  lsg = 998244353;
  for (long long i = 0; i <= n; i++) f[0][i] = f[i][0] = 1;
  for (long long i = 1; i <= n; i++)
    for (long long j = 1; j <= n; j++)
      (f[i][j] = f[i - 1][j - 1] * i + f[i][j - 1]) %= lsg;
  xx = max(f[x][y], f[y][x]);
  yy = max(f[x][z], f[z][x]);
  zz = max(f[z][y], f[y][z]);
  cout << xx * yy % lsg * zz % lsg << endl;
}
