4940: Sum of Remainders

内存限制:256 MB 时间限制:2 S
题面:传统 评测方式:文本比较 上传者:
提交:1 通过:1

题目描述

E. Sum of Remainders
time limit per test
2 seconds
memory limit per test
256 megabytes
input
standard input
output
standard output
Calculate the value of the sum: n mod 1 + n mod 2 + n mod 3 + ... + n mod m. As the result can be very large, you should print the value modulo 109+7 (the remainder when divided by 109+7).
The modulo operator a mod b stands for the remainder after dividing a by b. For example 10 mod 3 = 1.
Input
The only line contains two integers n,m (1≤n,m≤1013) − the parameters of the sum.
Output
Print integer s − the value of the required sum modulo 109+7.
Examples
Input
3 4
Output
4
Input
4 4
Output
1
Input
1 1
Output
0

输入样例 复制


输出样例 复制