In this task, you will be presented with a context passage, a question about that paragraph, and a possible answer to that question. The task is to check the validity of the answer. Answer with "Yes" or "No".
One example: Timothy likes to play sports. He spends his time after school playing basketball and baseball. Sometimes Timothy pretends he is a famous baseball pitcher for his favorite team with his friends. He plays with his friends Mandy and Andrew. Timothy also plays pretend when he is alone. He has an imaginary friend named Sean. Sean is an elephant who watches television with Timothy. Mandy likes playing baseball but she also likes to paint. Mandy's favorite class at school is art. She likes making pictures of flowers. Her teacher says she is a good artist. She painted a picture of a tree for her teacher. There were red and yellow leaves on it. It had apples on it. When Andrew goes home after baseball, he likes to eat a snack. He eats carrots and bananas. If he is a good boy his mom, Mrs. Smith, sometimes gives him milk and cookies. Afterwards, Andrew finishes his homework. <sep>Who does Timothy play with?<sep>Basketball and baseball
Solution is here: No
Explanation: Based on the passage Timothy plays with his friends Mandy and Andrew. So, the given answer is incorrect and the output should be "No".

Now, solve this: As Philip marched south, his opponents blocked him near Chaeronea, Boeotia. During the ensuing Battle of Chaeronea, Philip commanded the right wing and Alexander the left, accompanied by a group of Philip's trusted generals. According to the ancient sources, the two sides fought bitterly for some time. Philip deliberately commanded his troops to retreat, counting on the untested Athenian hoplites to follow, thus breaking their line. Alexander was the first to break the Theban lines, followed by Philip's generals. Having damaged the enemy's cohesion, Philip ordered his troops to press forward and quickly routed them. With the Athenians lost, the Thebans were surrounded. Left to fight alone, they were defeated. After the victory at Chaeronea, Philip and Alexander marched unopposed into the Peloponnese, welcomed by all cities; however, when they reached Sparta, they were refused, but did not resort to war. At Corinth, Philip established a "Hellenic Alliance" (modeled on the old anti-Persian alliance of the Greco-Persian Wars), which included most Greek city-states except Sparta. Philip was then named Hegemon (often translated as "Supreme Commander") of this league (known by modern scholars as the League of Corinth), and announced his plans to attack the Persian Empire. <sep>Who was left alone to fight and subsequently defeated?<sep>Spartans
Solution:
No