C=0 for t in range(int(input())): N=int(input()) C+=N*N if C>=10000000: assert(0) A=[0]+sorted(map(int,input().split())) B=[] for i in range(N,0,-1): B.append(A[i]-A[i-1]) B=B[::-1] K=N//2 DP=[[0]*(K+1) for i in range(N+1)] for i in range(1,N): for j in range(K+1): DP[i+1][j]=max(DP[i+1][j],DP[i][j]) if j