eggs      4 5 6 7 8
chickens  3 5 5 7 7

eggs      8 7 6 5 4
chickens  7 7 5 5 3

chickens \ eggs    8  7  6  5  4
               7   v  -  -  -  -     2 *
               7   *  v  -  -  -     1 *
               5         *  v  -     2 *
               5         v  -  -     1 *
               3               v     1 =
                                     4