N = int(input())
M1 = int(input())
A = list(map(int, input().split()))
M2 = int(input())
B = list(map(int, input().split()))
stairs = [1]*(N+1)
stairs[0] = 0
stairs[N] = 0
current = 0
for i in range(M1):
    current += A[i]
    stairs[current] = 0
current = N
for i in range(M2):
    current -= B[i]
    stairs[current] = 0
    
#print(stairs)

ans = sum(stairs)
print(ans)