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: Water erosion has similar consequences as wind erosion. 
Sentence2: exposure to water can cause erosion.

Ex Output:
Water


Ex Input:
Sentence1: soil is formed by weathering. 
Sentence2: Something described as loamy is formed by weathering.

Ex Output:
formed


Ex Input:
Sentence1: a stopwatch is used to measure time. 
Sentence2: Time can be measured with a clock or watch.

Ex Output:

measure