In late summer 1895, at the age of sixteen, Einstein sat the entrance examinations for the Swiss Federal Polytechnic in Zurich (later the Eidgenössische Polytechnische Schule). He failed to reach the required standard in several subjects, but obtained exceptional grades in physics and mathematics.^[22] On the advice of the Principal of the Polytechnic, he attended the Aargau Cantonal School in Aarau, Switzerland, in 1895-96 to complete his secondary schooling. While lodging with the family of Professor Jost Winteler, he fell in love with Winteler's daughter, Marie. (His sister Maja later married the Wintelers' son, Paul.)^[23] In January 1896, with his father's approval, he renounced his citizenship in the German Kingdom of Württemberg to avoid military service.^[24] (He acquired Swiss citizenship five years later, in February 1901.)^[25] In September 1896, he passed the Swiss Matura with mostly good grades (including a top grade of 6 in physics and mathematical subjects, on a scale of 1-6),^[26] and, though only seventeen, enrolled in the four-year mathematics and physics teaching diploma program at the ETH Zurich. Marie Winteler moved to Olsberg, Switzerland for a teaching post.