diff --git a/lines.cpp b/lines.cpp
index 153de92..7aa6598 100644
--- a/lines.cpp
+++ b/lines.cpp
@@ -84,12 +84,13 @@ int main(int argc, char *argv[])
 	// cv::waitKey(0);
 #endif
 
-	std::vector<std::vector<cv::Point>> verticals;
-	verticals.push_back(find_longest_line(hull, (maxdistances[0]+1)%hull.size(), maxdistances[1]));
+	std::vector<cv::Point> verticals[2];
+	// Between the two corners on the same side, the longest line is the vertical border of the book
+	verticals[0] = find_longest_line(hull, (maxdistances[0]+1)%hull.size(), maxdistances[1]);
 	std::cout << maxdistances[1] << std::endl;
 	std::cout << maxdistances[1]+1 << std::endl;
 	std::cout << (maxdistances[1]+1)%hull.size() << std::endl;
-	verticals.push_back(find_longest_line(hull, (maxdistances[1]+1)%hull.size(), maxdistances[0]));
+	verticals[1] = find_longest_line(hull, (maxdistances[1]+1)%hull.size(), maxdistances[0]);
 	free(maxdistances);
 
 	// theta is the angle of the line connecting point 1 and 2; it will be the