A female rat can give birth about six times a year, and a litter will contain about 10 little baby rats. Let's say you were imprisoned in a jail cell with one male rat (which you named Manfred) and one female rat (which you named Matilda). They had babies, and half the babies born the first year were male and half were female. All the baby rats began to reproduce after their first birthday. How many rats would you have to keep you company by the end of the second year?