anslist = []
def sarch(i, j, visited):

    if 0 < i:
        if visited[i - 1][j] == 0:
            visited[i - 1][j] = 1
            sarch(i - 1, j, visited)
        if 0 < j:
            if visited[i - 1][j - 1] == 0:
                visited[i - 1][j - 1] = 1
                sarch(i - 1, j - 1, visited)
        if j < len(visited[0]) - 1:
            if visited[i - 1][j + 1] == 0:
                visited[i - 1][j + 1] = 1
                sarch(i - 1, j + 1, visited)

    if i < len(visited) - 1:
        if visited[i + 1][j] == 0:
            visited[i + 1][j] = 1
            sarch(i + 1, j, visited)
        if 0 < j:
            if visited[i + 1][j - 1] == 0:
                visited[i + 1][j - 1] = 1
                sarch(i + 1, j - 1, visited)
        if j < len(visited[0]) - 1:
            if visited[i + 1][j + 1] == 0:
                visited[i + 1][j + 1] = 1
                sarch(i + 1, j + 1, visited)

    if 0 < j:
        if visited[i][j - 1] == 0:
            visited[i][j - 1] = 1
            sarch(i, j - 1, visited)
    if j < len(visited[0]) - 1:
        if visited[i][j + 1] == 0:
            visited[i][j + 1] = 1
            sarch(i, j + 1, visited)
    return visited


while True:
    w, h = map(int, input().split())
    if w == 0 and h == 0:
        break
    grid = [list(map(int, input().split())) for j in range(h)]
    visited = [[0 for i in range(w)] for j in range(h)]
    starti = 0
    startj = 0
    for i in range(h):
        for j in range(w):
            if grid[i][j] == 0:
                visited[i][j] = -1
            else:
                visited[i][j] = 0

    i = 0
    j = 0
    cnt = 0
    ans = 0
    #print(visited)
    while True:
        if i >= h:
            i = 0
            j = 0
        while True:
            cnt += 1
            if j >= w:
                j = 0
                break
            #print(visited[i][j], 100100)
            if visited[i][j] == 0:
                ans += 1
                visited[i][j] = 1
                visited = sarch(i, j, visited)
                cnt = 0
            j += 1
        i += 1
        #print(cnt, visited)
        if cnt > w * h:
            #print(10)
            break
    anslist.append(ans)

for i in anslist:
    print(i)


### FIXED CODE ###

import sys
sys.setrecursionlimit(10 ** 5)
anslist = []
def sarch(i, j, visited):

    if 0 < i:
        if visited[i - 1][j] == 0:
            visited[i - 1][j] = 1
            sarch(i - 1, j, visited)
        if 0 < j:
            if visited[i - 1][j - 1] == 0:
                visited[i - 1][j - 1] = 1
                sarch(i - 1, j - 1, visited)
        if j < len(visited[0]) - 1:
            if visited[i - 1][j + 1] == 0:
                visited[i - 1][j + 1] = 1
                sarch(i - 1, j + 1, visited)

    if i < len(visited) - 1:
        if visited[i + 1][j] == 0:
            visited[i + 1][j] = 1
            sarch(i + 1, j, visited)
        if 0 < j:
            if visited[i + 1][j - 1] == 0:
                visited[i + 1][j - 1] = 1
                sarch(i + 1, j - 1, visited)
        if j < len(visited[0]) - 1:
            if visited[i + 1][j + 1] == 0:
                visited[i + 1][j + 1] = 1
                sarch(i + 1, j + 1, visited)

    if 0 < j:
        if visited[i][j - 1] == 0:
            visited[i][j - 1] = 1
            sarch(i, j - 1, visited)
    if j < len(visited[0]) - 1:
        if visited[i][j + 1] == 0:
            visited[i][j + 1] = 1
            sarch(i, j + 1, visited)
    return visited


while True:
    w, h = map(int, input().split())
    if w == 0 and h == 0:
        break
    grid = [list(map(int, input().split())) for j in range(h)]
    visited = [[0 for i in range(w)] for j in range(h)]
    starti = 0
    startj = 0
    for i in range(h):
        for j in range(w):
            if grid[i][j] == 0:
                visited[i][j] = -1
            else:
                visited[i][j] = 0

    i = 0
    j = 0
    cnt = 0
    ans = 0
    #print(visited)
    while True:
        if i >= h:
            i = 0
            j = 0
        while True:
            cnt += 1
            if j >= w:
                j = 0
                break
            #print(visited[i][j], 100100)
            if visited[i][j] == 0:
                ans += 1
                visited[i][j] = 1
                visited = sarch(i, j, visited)
                cnt = 0
            j += 1
        i += 1
        #print(cnt, visited)
        if cnt > w * h:
            #print(10)
            break
    anslist.append(ans)

for i in anslist:
    print(i)