thanks lynn,

following is what i want..

2323 (2323 should have childs like 23231000,23232,23233000,232390 as its child))

23231000 ( should have nothing)

23232 (should have 232321,232329 as its child)

23233000(should have 23239010,23239020,23239030,23239040,23239090 as its child)

232390 ( should have nothing)

232321 (should have 23232110,23232190 as its child)

232329 (should have 23232910,23232990 as its child)

so the expected op is

2323,23231000,23232(232321(23232110,23232190),232329(23232910,23232990)),23233000(23239010,23239020,23239030,23239040,23239090),232390