import java.io.*; import java.util.*; import java.util.function.*; import java.util.stream.*; public class Main { public static void main(String[] args) throws Exception { Scanner sc = new Scanner(); int n = sc.nextInt(); boolean[] isDirty = new boolean[n + 1]; int m1 = sc.nextInt(); int current = 0; while (m1-- > 0) { current += sc.nextInt(); isDirty[current] = true; } int m2 = sc.nextInt(); while (m2-- > 0) { current -= sc.nextInt(); isDirty[current] = true; } System.out.println(IntStream.rangeClosed(0, n).filter(i -> !isDirty[i]).count()); } } class Scanner { BufferedReader br; StringTokenizer st = new StringTokenizer(""); StringBuilder sb = new StringBuilder(); public Scanner() { try { br = new BufferedReader(new InputStreamReader(System.in)); } catch (Exception e) { } } public int nextInt() { return Integer.parseInt(next()); } public long nextLong() { return Long.parseLong(next()); } public double nextDouble() { return Double.parseDouble(next()); } public String next() { try { while (!st.hasMoreTokens()) { st = new StringTokenizer(br.readLine()); } } catch (Exception e) { e.printStackTrace(); } finally { return st.nextToken(); } } }