 Menachem Oren

Mieczysław (Mendel) Chwojnik, later known as Dr. Menachem Oren (; 1903, Ruzhany, Russian Empire (now Belarus) – December 1962, Tel Aviv, Israel) was a notable chess master and mathematician.Chwojnik was the strongest Cracovian chess player in 1920s; thrice winner of the Cracow championships (1919, 1925, 1926).