N,M = map(int,input().split())
S = list(map(int,input().split()))
T = list(map(int,input().split()))
dp = [[1]*(M+1) for i in range(N+1)]

for i in range(N):
    for j in range(M+1):
        if S[i]==T[j-1]:
            dp[i+1][j]=dp[i+1][j-1] + dp[i][j]
        else:
            dp[i+1][j]=dp[i+1][j-1] +dp[i][j]-dp[i][j-1]
print(dp[-1][-1])