producing the wanted output at this point.
--- /dev/null
+x1y
+x2y
+x3y
+x4y
--- /dev/null
+x1y
+x2y
+x3y
+x4y
+x5y
+x6y
+x7y
--- /dev/null
+x1y
+x2y
+x3y
+x4y
+x5y
+x6y
+x7y
+x8y
+x9y
--- /dev/null
+x1y
+x2y
+x3y
+x4y
+x5y
+x6y
+x7y
+x8y
+x9y
+x0y
--- /dev/null
+x1y x2y x3y x4y - four matches here
--- /dev/null
+x1y x2y x3y x4y - four matches here
+x5y x6y x7y - three here
--- /dev/null
+x1y x2y x3y x4y - four matches here
+x5y x6y x7y - three here
+x8y x9y - two here
--- /dev/null
+x1y x2y x3y x4y - four matches here
+x5y x6y x7y - three here
+x8y x9y - two here
+x0y - one here