You will be given a definition of a task first, then some input of the task.
In this task, you're given a context, a sentence,  and a character. The sentence describes an action or job of the given character. Also, the context provides more information about the sentence or the character. Your task is to write the character's motivation by doing a specific job, which is given in the sentence. You can use context to find the motivation; however, all the inputs do not provide context. Also, in some inputs, there can be zero motivation; output, 'None' in this case.

Context: Mel was nine and wanted grow tall. He decided to take vitamins and eat healthy. He did special stretching exercises, too. On his tenth birthday he was measured again. 
 Sentence: He was ecstatic to see he had grown half a foot! 
 Character: Mel
Output:
None