#include <cstdio>
#include <iostream>
#include <string>
#include <vector>
using namespace std;

typedef vector<string> VS;

int rs, cs;
VS board;

// Is r,c within the bounds of the board?
bool valid(int r, int c) {
  return r >= 0 && r < rs && c >= 0 && c < cs;
}

// Get the value at r,c or empty if it is out of bounds
int get(int r, int c) {
  if (valid(r,c)) return board[r][c] != '0' ? 1 : 0;
  else return 0;
}

// Count the neighbors of r,c
int count(int r, int c) {
  return get(r-1,c) + get(r+1,c) + get(r,c-1) + get(r,c+1);
}

// Determine if a snake end at r,c can be grown
bool cangrow(int r, int c) {
  return 
    (valid(r-1,c) && get(r-1,c) == 0 && count(r-1,c) == 1) || 
    (valid(r+1,c) && get(r+1,c) == 0 && count(r+1,c) == 1) ||
    (valid(r,c-1) && get(r,c-1) == 0 && count(r,c-1) == 1) ||
    (valid(r,c+1) && get(r,c+1) == 0 && count(r,c+1) == 1);
}

// Flood-fill from a given r,c replacing f's with t's
void flood(int r, int c, char f, char t) {
  if (valid(r,c) && board[r][c] == f) {
    board[r][c] = t;
    flood(r-1,c,f,t);
    flood(r+1,c,f,t);
    flood(r,c-1,f,t);
    flood(r,c+1,f,t);
  }
}

int main(void) {
  while (1) {
    cin >> rs >> cs;
    if (rs == 0) break;
	
    // Read the board...
    board.clear();
    for (int i = 0; i < rs; ++i) {
      string s; cin >> s; board.push_back(s);
    }

    // For each square in the board...
    for (int r = 0; r < rs; ++r) {
      for (int c = 0; c < cs; ++c) {
	// If the square contains the end of an unmarked snake...
	if (board[r][c] == '1' && count(r,c) <= 1) {
	  // If the end can be grown...
	  if (cangrow(r,c)) {
	    // Mark the snake (overwrite it with 2's)
	    flood(r, c, '1', '2');
	  }
	}
      }
    }

    // All remaining '1' snakes are maximal.

    int count = 0;

    // For each square in the board...
    for (int r = 0; r < rs; ++r) {
      for (int c = 0; c < cs; ++c) {
	// If the square contains an unmaked snake...
	if (board[r][c] == '1') {
	  // Increment the counter
	  count += 1;
	  // and mark the snake (overwrite it with 2's)
	  flood(r, c, '1', '2');
	}
      }
    }

    printf("%d\n", count);

  }
  return 0;
}