Problem Statement

Given are three positive integers $A$, $B$, and $C$. Compute the following value modulo $998244353$:

∑a=1A​∑b=1B​∑c=1C​abc

Constraints

• 1≤A,B,C≤109

Sample Input 1

1 2 3

Sample Output 1

18

We have: $(1\times 1\times 1)+(1\times 1\times 2)+(1\times 1\times 3)+(1\times 2\times 1)+(1\times 2\times 2)+(1\times 2\times 3)=1+2+3+2+4+6=18$.

Sample Input 2

1000000000 987654321 123456789

Sample Output 2

951633476

Be sure to compute the value modulo $998244353$.