looking for 1047
call 1: [0..11], middle a[5] = 1030
  call 2: [6..11], middle a[8] = 1047
found at index 8
looking for 1003
call 1: [0..11], middle a[5] = 1030
  call 2: [0..4], middle a[2] = 1015
    call 3: [0..1], middle a[0] = 1003
found at index 0
looking for 1050
call 1: [0..11], middle a[5] = 1030
  call 2: [6..11], middle a[8] = 1047
    call 3: [9..11], middle a[10] = 1060
      call 4: [9..9], middle a[9] = 1052
not in the book
