import itertools

if __name__ == '__main__':
    h, w = map(int, input().split())
    matrix = [list(map(int, input().split())) for _ in range(h)]
    
    diffs = ((1, 0), (0, 1))
    counter = 0
    for x, y in itertools.product(range(h), range(w)):
        if matrix[x][y] == 0: continue
        
        counter += 1
        stack = [(x, y)]
        while stack:
            i, j = stack.pop()
            if not(0 <= i < h and 0 <= j < w and matrix[i][j] == 1): continue

            matrix[i][j] = 0
            for di, dj in diffs:
                ni, nj = i + di, j + dj
                if 0 <= ni < h and 0 <= nj < w: stack.append((ni, nj))
    
    print(counter)