皇帝的新衣（改编）(2)
You may ask why I knew so much? Because I was the diplomatic minister of the country. Or in other words, I was the spy sent by his enemy.
Then, everything was confirmed.
Question: What is the sum of the expected amount of wine stored during the first n days?
Input: The first line is k and n, and the second line is 2k numbers, respectively representing a[1],a[2]...a[k],f[k 1],f[k 2]...f[2k].答案需要除以10000000007取余.
本题输入：2 100
789 3453545 7767 7767
Then, everything was confirmed.
Question: What is the sum of the expected amount of wine stored during the first n days?
Input: The first line is k and n, and the second line is 2k numbers, respectively representing a[1],a[2]...a[k],f[k 1],f[k 2]...f[2k].答案需要除以10000000007取余.
本题输入：2 100
789 3453545 7767 7767
快新绿茶陷害新一
