Some "doo" and some "doo" not.

Belgrade has a number of really beautiful parks, large and small. Retired people on benches soak up the sun, lovers kiss in the shade of a tree, mothers keep a watchful eye on their children playing nearby. You can walk or sit on the grass too, if you dare. Up until fairly recently, there was no scoop law, and even now, strolling over the grass requires as much concentration as making your way through a mine field. You're more liable to soil your shoes in a small park; less grass for dogs to go on... The girl on the left is "doo-ing" her duty by picking up after her dog. Some "doo" not, as seen on the right.