class UnionFind():
    def __init__(self, n):
        self.n = n
        self.par = list(range(self.n))
        self.rank = [1] * n
        self.count = n
    def find(self, x):
        if self.par[x] == x:
            return x
        else:
            self.par[x] = self.find(self.par[x])
            return self.par[x]
    def unite(self, x, y):
        p = self.find(x)
        q = self.find(y)
        if p == q:
            return None
        if p > q:
            p, q = q, p
        self.rank[p] += self.rank[q]
        self.par[q] = p
        self.count -= 1
    def same(self, x, y):
        return self.find(x) == self.find(y)
    def size(self, x):
        return self.rank[x]
    def count(self):
        return self.count
h, w = map(int, input().split())
a = [list(map(int, input().split())) for i in range(h)]
UF = UnionFind(h * w)
for i in range(h):
    for j in range(1, w):
        if a[i][j] == a[i][j - 1] == 1:
            UF.unite(i * w + j, i * w + j - 1)
for j in range(w):
    for i in range(1, h):
        if a[i][j] == a[i - 1][j] == 1:
            UF.unite(i * w + j, (i - 1) * w + j)
print(UF.count - sum(i.count(0) for i in a))