Hi tutor. I've a simple question. I create a list containing numbers. list1=[1,2,4,8,16,32,64,128,512] # which is 2**0 ...2**10 If I wanted to find if a given number, 12 for example, is in the list would be easy. But, how about if x+y in the list equals the number (12) ? So, 8 + 4 for example. Maybe I am just going the wrong way here, and there is a easier way to do this.