import sys
input_stream = sys.stdin
cases = int(input_stream.readline())
""" 
Disclosure: I was struggling with the indexing idea.. 
and I got influenced by the solution in a stackoverflow post to improve my implementation.
It still reads like that solution instead of mine.. 
I was out of time anyway after submitting my naiver solution, so didn't get to take advantage of sneaking on the interwebs
"""
 
def next_pointer(lst, start):
    idx = start
    # 0 indexed
    out = start - 1
    while idx < len(lst) and lst[idx]:
        out = idx
        idx += 1
    return out
 
 
 
def line_list(input_stream):
  return map(int,input_stream.readline().strip().split())
 
 
for t in xrange(cases):
  n,k = line_list(input_stream)
  a,b,c,r = line_list(input_stream)
  # Storing 10^9 is expensive, do it in chunks
  # 4 worked for the input from facebook
  m = [0] * (4*k)
  # This is the lookup set guaranteed to not be > len(k)
  # Lookup is used more like a dictionary.. 
  # Each index stores the number of occurences of the value
  lookup = [0] * (k+1)
  m[0] = a
  if m[0] <= k:
      lookup[m[0]] = 1
  for i in xrange(1, k):
      # Linear Congruential Generator
      m[i] = (b * m[i-1] + c) % r
      if m[i] < k+1:
          lookup[m[i]] += 1
 
  pointer = next_pointer(lookup, 0)
  m[k] = pointer + 1
  pointer = next_pointer(lookup, pointer+2)
 
  for i in xrange(k+1, n):
      # Is the number > the index.. and have we seen it before?
      if m[i-k-1] > pointer or lookup[m[i-k-1]] > 1:
          m[i] = pointer + 1
          # If the item isn't in the range we're tracking, 
          # decrement the counter at that index.. 
          if m[i-k-1] <= k:
              lookup[m[i-k-1]] -= 1
          lookup[m[i]] += 1
          pointer = next_pointer(lookup, pointer+2)
      else:
          m[i] = m[i-k-1]
      if pointer == k:
          break
 
  if pointer != k:
    out = m[n-1]
  else:
    out = m[i-k + (n-i+k+k) % (k+1)]
  print 'Case #%d: %d' % (t+1, out)

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

20
1000000000 100000
1 1 0 2
1000000000 100000
999999999 1 999999999 1000000000
714311129 39521
9 5 9 999998192
220 88
1 8 3 58265
177 73
7 7 5 56401
131 74
1 9 10 78736
45068754 29153
2 9 5 999904402
73 26
5 8 4 54214
640834505 28785
3 9 1 999946125
186 75
68 16 539 186
1000000000 1
12 7 74 12
137 49
48 17 461 137
46 18
7 11 9 46
66 39
35 2 589 66
1000000000 100000
100000 1 0 1000000000
249718282 93729
1 5 6 999917908
497151700 96511
9 7 6 999919625
218492221 46085
3 7 1 999969453
1000000000 100000
99999 1 99999 100000
82 81
58 56 739 82