import java.util.Scanner; import java.util.*; public class Main { public static void main(String[] args) { Scanner in = new Scanner(System.in); int n = in.nextInt(); int ai = in.nextInt(); int m = in.nextInt(); Map<integer>> records = new HashMap<>(); for(int i = 0; i < m; i++) { String[] strs = in.next().split(","); int val1 = Integer.parseInt(strs[0]), val2 = Integer.parseInt(strs[1]); if(!records.containsKey(val1)) records.put(val1, new ArrayList<integer>()); if(!records.containsKey(val2)) records.put(val2, new ArrayList<integer>()); records.get(val1).add(val2); records.get(val2).add(val1); } int b= records.get(ai).size(); List<integer> lists=new ArrayList<integer>(); lists.add(ai); int index=0; while(lists.size()>index&&records.size()>0) { int tmp=lists.get(index); boolean a=false; for(Integer num:records.get(tmp)) { if(!lists.contains(num)) { lists.add(num); a=true; } } if(a) { records.remove(tmp); } index++; } System.out.println(lists.size()-1-b); } } //后面就改了下，对查过的记录进行Remove</integer></integer></integer></integer></integer>