data:image/png;base64,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data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAeAAAAFoCAYAAACPNyggAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAK1SURBVHhe7cExAQAAAMKg9U9tDB8gAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAgIsajf4AAXBXLv8AAAAASUVORK5CYII=It's somewhat artificial that we start with shape inputs for DRAW BRICK but have fixed values in ROWA and ROWB. Acknowledge that if students bring it up. The main reason we did this is that ROWB is easier if they can do the arithmetic instead of building algebraic expressions for the general case.3. The reason that the obvious attempt (with exactly half-size bricks at the ends) fails is that a rowB has an extra cement gap -- six of them instead of five. Since we're using a length of 4 for a cement gap, the two end bricks must be reduced by 4/2 = 2 steps each, to 13 instead of 30/2 = 15.30101310These magic numbers will have to be computed instead when we add more inputs later.2