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: Enveloped viruses make their own membranes. 
Sentence2: Some viruses make their own membranes.

Ex Output:
make


Ex Input:
Sentence1: if an object in a fluid is more dense than that fluid then that object will sink in that fluid because of gravity. 
Sentence2: Most seeds are more dense than water.

Ex Output:
dense


Ex Input:
Sentence1: if a habitat can no longer support animals then those animals will move to another area. 
Sentence2: When wildfowl's territory is destroyed, they must move to another area.

Ex Output:

another