It was at a cocktail party in New York that I met Stephanie. We exchanged our phone numbers and decided to meet each other soon. When she rang up and invited me to her house this is how she gave me the number of her house: “I live in a long street. Numbered on my side are the houses one, two, and three and so on. All the numbers on one side of me add up exactly the same as all the numbers on the other side of me. I know there are more than fifty houses on that side of the street, but not so many as five hundred”. Can you find Stephaine's house number?