class SnesPal
    {
        public int maxColors;
        
        public List<Color> colors;
        
        // ===================================================
        
        public static int Distance(SnesPal a, SnesPal b)
        {
            int maxColors   = a.maxColors;
            int numSame     = 0;
            int numDiff     = 0;
            
            // ------------------------------
            
            if(a.maxColors != b.maxColors)
            {
                throw new Exception("Merging different sized palettes!");
            }
            
            // add the number of colors in a that are not in b
            foreach(Color c in a.colors)
            {
                if( !b.colors.Contains(c) )
                {
                    numDiff += 1;
                }
                else
                {
                    numSame += 1;
                }
            }
            
            // add the number of colors in b that are not in a
            foreach(Color c in b.colors)
            {
                if( !a.colors.Contains(c) )
                {
                    numDiff += 1;
                }
            }
            
            if( (numDiff + numSame) > maxColors )
            {
                numDiff = maxColors;
            }
            
            return numDiff;
        }
        
        // ===================================================
        
        public static SnesPal Merge(SnesPal a, SnesPal b)
        {
            int maxColors = a.maxColors;
            
            SnesPal mergePal = new SnesPal();
            
            // ----------------------------------
            
            if( Distance(a,b) >= maxColors )
            {
                throw new Exception("Palettes are too large to merge");
            }
            
            // populate the merge palette with all the colors of a
            foreach(Color c in a.colors)
            {
                mergePal.colors.Add(c);
            }
            
            // now add all the colors that are in b but not in a.
            foreach(Color c in b.colors)
            {
                if( !mergePal.colors.Contains(c) )
                {
                    mergePal.colors.Add(c);
                }
            }
            
            return mergePal;
        }
    }