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: Protozoa make humans sick when they become human parasites. 
Sentence2: paramecium are single celled animals that make humans sick when they become human parasites.

Output: become


Input: Consider Input: Sentence1: a circle graph can be used to display percents. 
Sentence2: pie charts are circle graphs.

Output: circle


Input: Consider Input: Sentence1: Marine biomes are found in the salt water of the ocean. 
Sentence2: Marine biomes are found in large bodies of salt water.


Output: Marine