Generate an overlapping word between the given two sentences. When you find the overlapping words, they don't have to match exactly, e.g., "survival" and "survive" are valid overlapping words. Little words like "the" or "of" don't count! You must generate significant words which are not the stop words.

Ex Input:
Sentence1: Bacteria and Viruses Bacteria and viruses can cause diseases. 
Sentence2: bacteria can have a negative impact on an organism.

Ex Output:
Bacteria


Ex Input:
Sentence1: An electric current is a flow of electric charge. 
Sentence2: a magnet moving in a coil of copper wire can cause a flow of electric charge.

Ex Output:
charge


Ex Input:
Sentence1: Lakes are generally bigger and deeper than ponds. 
Sentence2: Lake trout season opens in Lake Huron and Lake Michigan, excluding the refuges.

Ex Output:

Lakes