B"For given integers n and m , let's call a pair of arrays a and b of integers good, if they satisfy the following conditions: Find the sum of |a| over all good pairs of arrays (a,b) . Since the answer can be very large, output it modulo 10^9 + 7 . The input consists of multiple test cases. The first line contains a single integer t (1 <= q t <= q 10^4) -- the number of test cases. The description of the test cases follows. The only line of each test case contains two integers n and m (1 <= q n, m <= q 5 cdot 10^6) . It is guaranteed that the sum of n over all test cases does not exceed 5 cdot 10^6 and the sum of m over all test cases does not exceed 5 cdot 10^6 . For each test case, output a single integer -- the sum of |a| over all good pairs of arrays (a,b) modulo 10^9 + 7 . In the first testcase, the good pairs of arrays are Hence the sum of the lengths would be {2 + 3 + 3} = 8 . "...