The kingdom ruled by a river in the palace inherited from its fathers. He decided to build a magnificent castle across the river and move the capital across the river. But the king dreamed one night that his crown was being carried by the river and that a shark was attacking him. He asked the court mathematician and astronomer to interpret his dream. "You are worried about the transfer of the capital and the conspiracy of the courtiers and the military," the mathematician said. By extending the riddle of wolves and sheep and plants, the capital can be moved to the other side of the river without any mishap. Happy Mubarak.

Born: April 22, 1936 (age 83 years), Iran Mehdi Behzad is an Iranian mathematician specializing in graph theory. He introduced his total coloring theory during his Ph.D. studies in 1965. Despite the active work during the last 50 years this conjecture remains as challenging as it is open. Wikipedia