P26185 [AtCoder] Simple Math
入门
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