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: After a seed is planted it is watered. 
Sentence2: seeds need water.

Ex Output:
seed


Ex Input:
Sentence1: Fission is a type of reproduction, but a baby is the result of sexual reproduction. 
Sentence2: the fallopian tubes are used to make babies.

Ex Output:
baby


Ex Input:
Sentence1: Endocrine hormones travel throughout the body in the blood. 
Sentence2: Breathing affects the flow of hormones through the endocrine system.

Ex Output:

Endocrine