N = int(input())
M1 = int(input())
A = list(map(int,input().split()))
M2 = int(input())
B = list(map(int,input().split()))

import itertools
A_sum = list(itertools.accumulate(A))
B_sum = list(itertools.accumulate(B))
li = A_sum + [N-B[i] for i in range(M2)] + [0]
print(N+1-len(set(li)))