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: healing requires rest. 
Sentence2: Healing and cell regeneration follows.

Output: healing


Input: Consider Input: Sentence1: when a body of water receives more water than it can hold , a flood occurs. 
Sentence2: Floods are deadly, floods are devastating.

Output: flood


Input: Consider Input: Sentence1: completing a circuit causes electricity to flow through that circuit. 
Sentence2: completing a circuit causes electrons to flow through that circuit.


Output: causes