Originally what was the total strength of security council of United Nations ?

Under the original 1945 United Nations Charter (Article 23), the total membership of the UN Security Council was 11—comprising 5 permanent members (China, France, the Soviet Union, the United Kingdom, and the United States) and 6 non-permanent members. An amendment to the Charter adopted in 1963 and entering into force in August 1965 expanded the Council to 15 members by increasing non-permanent seats from 6 to 10.