col, row = map(int, input().split())
map_list = [[0]* (col+2)]
for _ in range(row):
    map_list.append([0] + list(map(int, input().split())) + [0])
map_list.append(map_list[0])

def check(x, y):
    lands = [[x,y]]
    
    while lands:
        x, y = lands.pop()
        map_list[y][x] = 0
        # down 
        if map_list[y+1][x] == 1:
            lands.append([x, y+1])
        # right
        if map_list[y][x+1] == 1:
            lands.append([x+1, y])
        # up
        if map_list[y-1][x] == 1:
            lands.append([x, y-1])
        # left
        if map_list[y][x-1] == 1:
            lands.append([x-1, y])

count = 0
for r in range(1, row+1):
    for c in range(1, col+1):
        if map_list[r][c] == 1:
            check(c, r)
            count += 1

print(count)

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