CF869C The Intriguing Obsession

 1 #include <bits/stdc++.h>
 2 using namespace std;
 3 typedef long long ll;
 4 const ll mod = 998244353;
 5 ll dp[5005][5005];
 6 int main()
 7 {
 8     ll a, b, c;
 9     while (cin >> a >> b >> c)
10     {
11         for (int i = 0; i <= 5000; i++) dp[i][0] = dp[0][i] = 1;
12         for (int i = 1; i <= 5000; i++)
13         {
14             for (int j = 1; j <= 5000; j++)
15             {
16                 dp[i][j] = (dp[i - 1][j] + j * 1LL * dp[i - 1][j - 1] % mod) % mod;
17             }
18         }
19         cout << dp[a][b] * dp[a][c] % mod * dp[b][c] % mod << endl;
20     }
21     return 0;
22 }