Let's say that your neighborhood has a population of snails, which come out onto the sidewalk when the sprinklers come on, and the rest of the time they hide in the vegetation. If you catch 31, and mark them and, then, a week later, after they have had a chance to disperse into the population, you catch 26, and 13 have marks on them, what is the estimated size of the population? Report your answer rounded to the nearest whole number.