Republic was the first and only instance of the South Korean government using a parliamentary system instead of a presidential or semi-presidential system. The Democratic Party, which had been in the opposition during the First Republic, easily gained power; Rhee's former opponent Chang Myon became Prime Minister. The new legislature was bicameral, with the House of Representatives as the lower house and the House of Councillors as the upper house. Yun Bo-seon was elected as the second President of South Korea on 13 August 1960. Politics Freedom The Second Republic repealed the severe curbs on political expression that had been in place under the Rhee regime, and as a result, freedom returned and an increase in political activity. Much of this activity was from leftist and student groups, which had been instrumental in the overthrow of the First Republic. Membership of unions and activity grew rapidly during the later months of 1960. Estimates suggest around 2,000 demonstrations were held during eight months of the Second Republic. Under pressure from the left-wing, the Chang government carried out a series of purges of military and police officials who had been involved in anti-democratic activities or corruption during the First Republic. A special law to this effect was passed on 31 October 1960. Around 40,000 people were placed under investigation; of these, more than 2,200 government officials and 4,000 police officers were purged. In addition, the government considered reducing the size of the South Korean Army by 100,000, although this plan was shelved. Economy The Second Republic government was faced with mounting instability in economic terms as well, seeing unemployment and wholesale prices also rose during this period. The won lost half of its value against the US dollar between fall 1960 and spring 1961. The government formulated a five-year economic plan based around agriculture and light industry to decrease unemployment, although it was unable to act on it prior to being overthrown. Foreign relations Chang's government resumed negotiations for the normalization of diplomatic relations between Korea and Japan, which had not progressed under the Rhee regime that had existed since the end of Japanese rule. The Second Republic established diplomatic relations with many newly established countries, with Sohn Won-yil, the first ambassador to West Germany, attending the independence ceremonies of Cameroon, Togo, Guinea, Mali, Nigeria, and Morocco. Dissolution The Second Republic suffered from numerous political, economic, and social issues that were both