题目描述
Problem Statement
Given are three positive integers A, B, and C. Compute the following value modulo 998244353:
$\sum_{a=1}^{A} \sum_{b=1}^{B} \sum_{c=1}^{C}$ abc
Input
Input is given from standard input in the following format:
A B C
Output
Print the value modulo 998244353.
Constraints
- $1 \leq A, B, C \leq 10^9$
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.
输入格式
见题面 Input 部分
输出格式
见题面 Output 部分
样例输入
1 2 3
样例输出
18