Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Great investment in your health

I am a high school teacher and started taking this product at the beginning of the school year. I typically get every cold and flu bug that slinks through the school. I take one pill 5 days a week and I have not been sick once this school year. We are at the end of February and I am convinced that this is the best product I have ever bought to fight illness.