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: the moon revolving around the Earth causes the phases of the moon. 
Sentence2: Lets start our discussion of the Moon's phases with the New Moon phase.

Ex Output:
phases


Ex Input:
Sentence1: Average vehicle speed rises by only 0.3 miles per hour. 
Sentence2: a speedometer measures miles per hour.

Ex Output:
hour


Ex Input:
Sentence1: Temperature falls from lower to higher altitudes. 
Sentence2: the mountains have lower temperatures.

Ex Output:

Temperature