8809 = 6 5555 = 0 7111 = 0 8193 = 3 2172 = 0 8096 = 5 6666 = 4 1012 = 1 1111 = 0 7777 = 0 3213 = 0 9999 = 4 7662 = 2 7756 = 1 7753 = 0 6855 = 3 0000 = 4 9881 = 5 2222 = 0 5531 = 0 3333 = 0 2581 = ??? [spoiler]This problem can be solved by preschool children in five to ten minutes, by programmers in an hour and by people with higher education in... Well solve for ??? [/spoiler]