Think Outside the Box
1. Draw a single loop that connects the dots on the grid. The loop may only travel horizontally or vertically, and all turns are at 90 degree angles (no diagonals). The loop may only turn at the dots. The interior of the loop must be a single polygon. In other words the loop cannot cross itself.
2. All numbers inside the grid indicate how many of the four edges of the imaginary square surrounding the numbers are part of the loop. For example the number 3 would be surrounded by 3 edges and 2 would be surrounded by 2 edges.