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: moss causes chemical weathering. 
Sentence2: If the moss was completely dried then it is dead.

Output: moss


Input: Consider Input: Sentence1: Mammals depend on the vegetation for food and shelter. 
Sentence2: Mammals are Heterotrophs.

Output: Mammals


Input: Consider Input: Sentence1: erosion can cause a landslide. 
Sentence2: With the rain comes floods, and with the floods come erosion and landslides.


Output: erosion