Mason worked on the school project for 13 minutes. Shane worked 7 more minutes than Mason and 16 more minutes than Jay. How many minutes did the students work on the project altogether?

m = 13

s = m+7 = 13 + 7 = 20
s = j+16
so j = s-16 = 20-16 = 4
13 + 20 + 4 = ?