1733 - LL && Prime Matrix
Time Limit : 1 Second
Memory Limit : 64 MB
Submission: 0
Solved: 0
- Description
Wust_LL is a math dalao(Chinglish). One day, he define a function: f(i,j), the value of which equals to the sum of all prime numbers which can divide LCM(i,j). LCM(i,j) means the Lowest Common Multiple of integer i and integer j.
Now Wust_LL gets a Matrix with n rows and m columns. The value
of Matrix[i][j]=f(i,j). He wants to know the sum of the Matrix[i][j](1≤i≤n,1≤j≤m).
- Input
Each test case contains only one line with two integers n,m(1≤n,m≤10^6)
- Output
For each case, output an answer modulo 10^9+7.
- sample input
-
2 2 4 2
- sample output
-
6 18
- hint
we assume is not a prime.
- source
- WUST