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: Ribosomes are small organelles where proteins are made. 
Sentence2: Ribosomes are assembled inside the nucleus.

Ex Output:
Ribosomes


Ex Input:
Sentence1: Heterotrophs get food by eating other living things. 
Sentence2: fish eat other living things.

Ex Output:
living


Ex Input:
Sentence1: Some birds are pollinators that co-evolved with plants. 
Sentence2: Some animals with feathers are pollinators.

Ex Output:

pollinators