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.

Input: Consider Input: Sentence1: a battery converts chemical energy into electrical energy. 
Sentence2: Battery electricity comes conversion.

Output: battery


Input: Consider Input: Sentence1: Fish are the first known true chordates. 
Sentence2: Fish are the first known animal with a backbone.

Output: Fish


Input: Consider Input: Sentence1: Climate influences plant growth, biodiversity, and adaptations of land organisms. 
Sentence2: All plants are of bush type.


Output: plant