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: if an organism becomes too hot then that organism may die. 
Sentence2: if an organism overheats then that organism may die.

Ex Output:
die


Ex Input:
Sentence1: For example, insulin is a protein hormone. 
Sentence2: Insulin is produced in a part of the cell called the ribosome.

Ex Output:
insulin


Ex Input:
Sentence1: Well, the elbow is a hinged joint. 
Sentence2: Triceps contracting causes a person 's hinged joint to straighten.

Ex Output:

hinged