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: If there is an increase in UV radiation, the risks go up for all types of skin cancer. 
Sentence2: Ozone depletion increases the risks for all types of skin cancer.

Output: all


Input: Consider Input: Sentence1: bacteria cause food to spoil. 
Sentence2: Food poisoning occurs when spoiled food is eaten.

Output: spoil


Input: Consider Input: Sentence1: Hormonal production is regulated by enzymes. 
Sentence2: enzymes control hormones.


Output: enzymes