loop do
????n = gets.to_i
????m = gets.to_i
????break if n == 0
????r = []
????m.times { r << gets.split.map(&:to_i) }
??
????friends = r.select {|(a,b)| a == 1 || b == 1 }.map {|(a,b)| a == 1 ? b : a }
????foafs = r.select {|(a,b)| a != 1 && b != 1 && (friends.include?(a) || friends.include?(b)) }.flatten - friends
??
????puts friends.size + foafs.size
end