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

// 四个方向：上下左右
const int dx[] = {-1, 1, 0, 0};
const int dy[] = {0, 0, -1, 1};

void dfs(vector<vector<int>>& grid, vector<vector<bool>>& visited, int x, int y) {
    int m = grid.size();
    int n = grid[0].size();
    
    // 边界检查：超出范围、已访问、是0则返回
    if (x < 0 || x >= m || y < 0 || y >= n || visited[x][y] || grid[x][y] == 0) {
        return;
    }
    
    visited[x][y] = true; // 标记为已访问
    
    // 遍历四个方向
    for (int i = 0; i < 4; ++i) {
        int nx = x + dx[i];
        int ny = y + dy[i];
        dfs(grid, visited, nx, ny);
    }
}

int main() {
    int m, n;
    cin >> m >> n;
    cin.ignore(); // 忽略换行符，避免影响后续getline
    
    vector<vector<int>> grid(m, vector<int>(n));
    for (int i = 0; i < m; ++i) {
        string line;
        getline(cin, line);
        for (int j = 0; j < n; ++j) {
            grid[i][j] = line[j] - '0'; // 字符转整数
        }
    }
    
    vector<vector<bool>> visited(m, vector<bool>(n, false));
    int count = 0;
    
    for (int i = 0; i < m; ++i) {
        for (int j = 0; j < n; ++j) {
            // 找到未访问的非0数字，启动DFS
            if (!visited[i][j] && grid[i][j] != 0) {
                count++;
                dfs(grid, visited, i, j);
            }
        }
    }
    
    cout << count << endl;
    return 0;
}