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.

Example Input: Sentence1: Conventional myosin is required for cytokinesis . 
Sentence2: Conventional myosin is required for the final stage of cell division.
Example Output: Conventional

Example Input: Sentence1: Information on DNA is organized into genes. 
Sentence2: DNA codes for proteins.
Example Output: DNA

Example Input: Sentence1: Water enters the body of the sponge through the osculum. 
Sentence2: Sperm are released into the surrounding water through the sponge's body part.
Example Output:
body