5-10.py

n,m = map(int,input().split())

graph = []
for i in range(n):
    graph.append(list(map(int,input())))


def dfs(x,y):

    if x<=-1 or x>=n or y<=-1 or y>=m:
        return False

    if graph[x][y]==0:
        graph[x][y] = 1

        dfs(x-1,y)
        dfs(x+1,y)
        dfs(x,y-1)
        dfs(x,y+1)

        return True
    return False

result = 0

for i in range(n):
    for j in range(m):

        if dfs(i,j)==True:
            result += 1
print(result)