def solve():
  n = int(input())
  a = list(map(int, input().split()))
  inf = int(1e18)
  dp = [-inf] * 6
  dp[0] = dp[1] = 0
  for i in range(n):
    ndp = [-inf] * 6
    for j in range(3):
      if j < 2:
        ndp[2 * j + 2] = max(dp[2 * j], dp[2 * j + 1]) + a[i]
        ndp[2 * j + 3] = max(dp[2 * j], dp[2 * j + 1]) - a[i]
      ndp[2 * j] = max(ndp[2 * j], dp[2 * j] + a[i])
      ndp[2 * j + 1] = max(ndp[2 * j + 1], dp[2 * j + 1] - a[i])
    dp, ndp = ndp, dp
  print(max(dp[4], dp[5]))

t = int(input())
for i in range(t):
  solve()