#![allow(unused_imports)]
use std::io::{ self, Write };
use std::str::FromStr;
use std::cmp::{ min, max };
use std::collections::{ BinaryHeap, VecDeque };

#[allow(unused_macros)]
macro_rules! trace {
    ($var:expr) => {
        let _ = writeln!(&mut std::io::stderr(), ">>> {} = {:?}", stringify!($var), $var);
    };
    ($($args:expr),*) => { trace!(($($args),*)) }
}

#[allow(unused_macros)]
macro_rules! put {
    ($var:expr) => {
        let _ = writeln!(&mut std::io::stdout(), "{}", $var);
    };
    ($var:expr, $($args:expr),*) => {
        let _ = write!(&mut std::io::stdout(), "{} ", $var);
        put!($($args),*);
    };
}

const M: usize = 1_000_000_007;

fn main() {
    let mut sc = Scanner::new();
    let h: usize = sc.cin();
    let w: usize = sc.cin();
    let mut memo = vec![vec![false; w]; h];
    for i in 0..h {
        for j in 0..w {
            let d: usize = sc.cin();
            if d == 1 {
                memo[i][j] = true;
            }
        }
    }

    let mut ans = 0;

    for i in 0..h {
        for j in 0..w {

            if !memo[i][j] { continue }

            ans += 1;
            let mut stack = VecDeque::new();
            stack.push_back((i, j));

            while let Some((i, j)) = stack.pop_front() {
                if !memo[i][j] { continue }
                memo[i][j] = false;
                if i < h - 1 { stack.push_back((i+1, j)); }
                if i > 0 { stack.push_back((i-1, j)); }
                if j < w - 1 { stack.push_back((i, j+1)); }
                if j > 0 { stack.push_back((i, j-1)); }
            }
        }
    }

    put!(ans);

}

#[allow(dead_code)]
struct Scanner { stdin: io::Stdin, buffer: VecDeque<String>, }
#[allow(dead_code)]
impl Scanner {
    fn new() -> Scanner { Scanner { stdin: io::stdin(), buffer: VecDeque::new() } }
    fn reserve(&mut self) {
        while self.buffer.len() == 0 {
            let mut line = String::new();
            let _ = self.stdin.read_line(&mut line);
            for w in line.split_whitespace() {
                self.buffer.push_back(String::from(w));
            }
        }
    }
    fn cin<T: FromStr>(&mut self) -> T {
        self.reserve();
        match self.buffer.pop_front().unwrap().parse::<T>() {
            Ok(a) => a,
            Err(_) => panic!("parse err")
        }
    }
}