Given the task definition and input, reply with output. In this task, you are given two sentences in the English language (Sentence 1 and Sentence 2). Your task is to identify the connecting word between the two sentences.

Sentence 1:In the above , function ( ) can be called by different threads without any problem . Sentence 2:But , if the function is used in a reentrant interrupt handler and a second interrupt arises inside the function , the second routine will hang forever .

but