15. In a room, there are 3 people (Xiao Wang, Xiao Zhang, Xiao Li) and 1 dog. Every morning, the 3 people get up and make some cookies so that they can eat them whenever they are hungry. One morning, Xiao Wang was the first to leave for work. Before leaving, he threw 1 cookie to the dog and took and ate the remaining $1 / 3$; Xiao Zhang was the second to leave for work. Before leaving, he threw 1 cookie to the dog and took and ate the remaining $1 / 3$; Xiao Li was the third to leave for work. Before leaving, he threw 1 cookie to the dog and took and ate the remaining $1 / 3$; In the evening, after all 3 people returned home, they threw 1 cookie to the dog and then divided and ate the remaining cookies. Throughout the process, none of the cookies needed to be broken. Therefore, the minimum number of cookies Xiao Wang ate is ____.
【Analysis】Assuming each person gets $\mathrm{n}$ pieces at night, then the total number is $\left\{\left[(3 n+1) \div \frac{2}{3}+1\right] \div \frac{2}{3}+1\right\} \div \frac{2}{3}+1=\frac{81 n+65}{8}$ is an integer, $\mathrm{n}$ is at least 7, the total number is 79, so the minimum number of cookies eaten is $\frac{79-1}{3}+7=33$ (pieces).