h, w = map(int, input().split())
A = [list(map(int, input().split())) for _ in range(h)]

def Find(x, par):
    if par[x] < 0:
        return x
    else:
        par[x] = Find(par[x], par)
        return par[x]

def Unite(x, y, par, rank):
    x = Find(x, par)
    y = Find(y, par)

    if x != y:
        if rank[x] < rank[y]:
            par[y] += par[x]
            par[x] = y
        else:
            par[x] += par[y]
            par[y] = x
            if rank[x] == rank[y]:
                rank[x] += 1

def Same(x, y, par):
    return Find(x, par) == Find(y, par)

def Size(x, par):
    return -par[Find(x, par)]

par = [-1]*(h*w)
rank = [0]*(h*w)

for i, row in enumerate(A):
    for j, a in enumerate(row):
        v = i*w+j
        if a == 1:
            for di, dj in (-1, 0), (1, 0), (0, -1), (0, 1):
                ni, nj = i+di, j+dj
                if 0 <= ni < h and 0 <= nj < w:
                    if A[ni][nj] == 1:
                        u = ni*w+nj
                        Unite(v, u, par, rank)
S = set()
for i, row in enumerate(A):
    for j, a in enumerate(row):
        v = i*w+j
        if a == 1:
            S.add(Find(v, par))
print(len(S))