 Complete the following phrase:  Mayer, the son of a farmer, was born on 19 August 1917 in Konstanz at the Bodensee. Konstanz at the time was in the Grand Duchy of Baden of the German Empire. Mayer grew up on his parents farm named Hauserhof and spent his spare time at the glider airfield at the Bellenberg near Engen. He went to school at the Langemarck-Realgymnasiuma secondary school built on the mid-level Realschule to achieve the Abitur university entry qualificationin Singen. Today, the Langemarck-Realgymnasium, which had been named after the location of the World War I 