An artist paints a mural on the wall of a building in Vukovar, Croatia, May 27, 2021. Street art festival VukovART, which features murals created by world-famous artists on the walls and sidewalks, is held in Vukovar for the fifth year in a row. (Davor Javorovic/Pixsell via Xinhua)

　　A mural is seen on the river bank in Vukovar, Croatia, May 27, 2021. Street art festival VukovART, which features murals created by world-famous artists on the walls and sidewalks, is held in Vukovar for the fifth year in a row. (Davor Javorovic/Pixsell via Xinhua)

　　A mural is seen on the wall of a building in Vukovar, Croatia, May 27, 2021. Street art festival VukovART, which features murals created by world-famous artists on the walls and sidewalks, is held in Vukovar for the fifth year in a row. (Davor Javorovic/Pixsell via Xinhua)

　　A mural is seen on the wall of a building in Vukovar, Croatia, May 27, 2021. Street art festival VukovART, which features murals created by world-famous artists on the walls and sidewalks, is held in Vukovar for the fifth year in a row. (Davor Javorovic/Pixsell via Xinhua)