from sys import stdin, stdout
input = lambda: stdin.readline().rstrip()
write = stdout.write

def main():
    H, W = map(int, input().split())
    A = stdin.read().replace(' ', '').splitlines()

    ans = 0
    for s in A:
        ans += ponds(s)

    for i in range(H - 1):
        n = int(A[i]) & int(A[i+1])
        ans -= ponds(str(n))
    print(ans)

def ponds(s):
    s = s.replace('00', '0').strip('0')
    cnt = s.count('0') + 1 if s != '' else 0
    return cnt

main()