A heuristic is a method that might not always find the best solution but is guaranteed to find a good solution in a reasonable time. This method is basically a depth-first search as complete solutions must be created before testing. It is often called the British Museum method as it is like looking for an exhibit at random. A heuristic is needed to sharpen up the search. Consider the problem of four 6-sided cubes, and each side of the cube is painted in one of four colors. The four cubes are placed next to one another and the problem lies in arranging them so that the four available colors are displayed whichever way the 4 cubes are viewed. The problem can only be solved if there are at least four sides colored in each color and the number of options tested can be reduced using heuristics if the most popular color is hidden by the adjacent cube.