class UnionFind:
    def __init__(self, sz):
        self.par = [-1] * sz

    def merge(self, u, v):
        u = self.leader(u)
        v = self.leader(v)
        if u == v:
            return
        self.par[u] += self.par[v]
        self.par[v] = u

    def same(self, u, v):
        if self.leader(u) == self.leader(v):
            return True
        return False

    def leader(self, pos):
        if self.par[pos] < 0:
            return pos
        self.par[pos] = self.leader(self.par[pos])
        return self.par[pos]

    def size(self, x):
        return -self.par[self.leader(x)]

H,W = map(int,input().split())
A = [list(map(int,input().split())) for _ in range(H)]
UF = UnionFind(H*W)
dx = [0, 0, -1, 1]
dy = [-1, 1, 0, 0]
for i in range(H):
    for j in range(W):
        if A[i][j]:
            for k in range(4):
                nx,ny = i + dx[k], j + dy[k]
                if nx < 0 or H <= nx or ny < 0 or W <= ny:
                    continue
                if A[nx][ny]:
                    UF.merge(i * W + j, nx * W + ny)
        else:
            UF.par[i*W+j] = 0
ans = 0
for i in range(H):
    for j in range(W):
        if UF.par[i*W+j] < 0:
            ans += 1
print(ans)