Every day, farmer john milks his 8 dairy cows, named bessie, buttercup, belinda, beatrice, bella, blue, betsy, and sue. the cows are rather picky, unfortunately, and require that farmer john milks them in an order that respects n constraints (1≤n≤7). each constraint is of the form "x must be milked beside y", stipulating that cow x must appear in the milking order either directly after cow y or directly before cow y.

farmer john determine an ordering of his cows that satisfies all of these required constraints. it is guaranteed that an ordering is always possible. if several orderings work, then output the one that is alphabetically first. that is, the first cow should have the alphabetically lowest name of all possible cows that could appear first in any valid ordering. among all orderings starting with this same alphabetically-first cow, the second cow should be alphabetically lowest among all possible valid orderings, and so on.