Six second-graders tried tossing a ball into a basket ten times each. Their teacher then suggested a different way of tossing the ball, and the six students tried again. The number of successful tosses, before and after the teacher's suggestion, are shown below.
Student A B C D E F
B4 suggestion ( out of 10) 3 5 7 3 5 7
After suggestion (out of 10) 4 5 5 4 5 5
Find the sum of the positive and negative rank sums as in a Wilcoxon signed-rank test.