About 3,000 Orthodox Christians in Finland belong to the Russian Orthodox Church . They are organized into two parishes. There have also been plans to establish a separate Russian diocese in Finland. Parishes maintain five churches and chapels. St. Nicholas Orthodox Parish  in Helsinki is the largest with 2,600 members.  The parish was established in 1927, and a large part of its members are Finnish citizens. Recently, the parish has been growing fast due to a new wave of repatriates and immigrants from Russia. Rooted in the 1920s' Private Orthodox Society in Viipuri , the Intercession Orthodox Parish  was officially formed in 2004, also in Helsinki, and has some 350 members today. Both have registered themselves as separate religious organizations. Unlike the Finnish Orthodox Church, the Russian Orthodox Church in Finland follows the Julian calendar.
Question: How many is the difference between the total number of Russian Orthodox christians in Finland and the number of members in St. Nicholas Orthodox Parish?
Answer: 400