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: Basically, heat is energy. 
Sentence2: Head hair is especially important in preventing energy loss from the body.

Ex Output:
energy


Ex Input:
Sentence1: Arthropods Arthropods have jointed segmented exoskeletons. 
Sentence2: Insects have jointed segmented exoskeletons.

Ex Output:
exoskeletons


Ex Input:
Sentence1: Consumers take in food by eating producers or other living things. 
Sentence2: Decomposers produce nutrients for producers.

Ex Output:

producers