#include <bits/stdc++.h>
using namespace std;
long long a, b, c;
const long long MOD = 998244353ll;
const int MAXN = 5005;
long long fans = 0;
long long cx[MAXN][MAXN];
long long ax[MAXN];
long long solve(long long x, long long y) {
  long long ans = 0;
  long long mn = min(x, y);
  long long mx = max(x, y);
  ans += 1;
  ax[0] = 1;
  for (long long i = 1; i <= mx; i++) ax[i] = (ax[i - 1] * (mx - i + 1)) % MOD;
  for (long long i = 1; i <= mn; i++) ans = (ans + cx[mn][i] * ax[i]) % MOD;
  return ans;
}
int main() {
  cx[1][0] = cx[1][1] = 1;
  for (int i = 2; i < MAXN; i++) {
    cx[i][0] = 1;
    for (int j = 1; j < MAXN; j++)
      cx[i][j] = (cx[i - 1][j] + cx[i - 1][j - 1]) % MOD;
  }
  cin >> a >> b >> c;
  long long aa, bb, cc;
  aa = solve(a, b) % MOD;
  bb = solve(c, b) % MOD;
  cc = solve(c, a) % MOD;
  fans = (aa * bb) % MOD;
  fans = (fans * cc) % MOD;
  cout << fans << endl;
  return 0;
}
