Sum of Cubes

You are given an undirected graph G = (V, E). We define a function f(s) for s ⊆ V to be the number of edges in the induced subgraph of s. The problem asks you to calculate the sum of f(s)k over all s in 2|V| subsets of V. As the answer could be very large, output it modulo (109+7). Input The first line of input contains an integer T denoting the number of test cases. For each test case, th