import sys
from collections import deque

def main():
    H, W = map(int, sys.stdin.readline().split())
    grid = []
    for _ in range(H):
        row = list(map(int, sys.stdin.readline().split()))
        grid.append(row)
    
    count = 0
    dirs = [ (-1, 0), (1, 0), (0, -1), (0, 1) ]
    
    for i in range(H):
        for j in range(W):
            if grid[i][j] == 1:
                count += 1
                # Start BFS to mark all connected cells
                q = deque()
                q.append((i, j))
                grid[i][j] = 0
                while q:
                    x, y = q.popleft()
                    for dx, dy in dirs:
                        nx = x + dx
                        ny = y + dy
                        if 0 <= nx < H and 0 <= ny < W and grid[nx][ny] == 1:
                            grid[nx][ny] = 0
                            q.append((nx, ny))
    print(count)

if __name__ == '__main__':
    main()