#include <algorithm>
#include <iomanip>
#include <array>
#include <bitset>
#include <cassert>
#include <cmath>
#include <cstdio>
#include <deque>
#include <functional>
#include <iostream>
#include <iterator>
#include <map>
#include <queue>
#include <set>
#include <string>
#include <sstream>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <numeric>
#include <vector>
#include <climits>
using namespace std;
#if __has_include(<atcoder/all>)
#include <atcoder/all>
using namespace atcoder;
#endif
#define GET_MACRO(_1, _2, _3, NAME, ...) NAME
#define _rep(i, n) _rep2(i, 0, n)
#define _rep2(i, a, b) for(int i = (int)(a); i < (int)(b); i++)
#define rep(...) GET_MACRO(__VA_ARGS__, _rep2, _rep)(__VA_ARGS__)
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
using i64 = long long;
template<class T, class U>
bool chmin(T& a, const U& b) { return (b < a) ? (a = b, true) : false; }
template<class T, class U>
bool chmax(T& a, const U& b) { return (b > a) ? (a = b, true) : false; }

template<typename T>istream& operator>>(istream&i,vector<T>&v){rep(j,v.size())i>>v[j];return i;}
template<typename T>string join(vector<T>&v){stringstream s;rep(i,v.size())s<<' '<<v[i];return s.str().substr(1);}
template<typename T>ostream& operator<<(ostream&o,vector<T>&v){if(v.size())o<<join(v);return o;}
template<typename T>string join(vector<vector<T>>&vv){string s="\n";rep(i,vv.size())s+=join(vv[i])+"\n";return s;}
template<typename T>ostream& operator<<(ostream&o,vector<vector<T>>&vv){if(vv.size())o<<join(vv);return o;}
template<class T> using pq = priority_queue<T, vector<T>, greater<T>>;
int di[] = {-1, 1, 0, 0};
int dj[] = {0, 0, 1, -1};

int main() {
    int h, w;
    cin >> h >> w;

    vector table(h, vector<int>(w));
    rep(i, h) rep(j, w) cin >> table[i][j];

    int ans = 0;

    rep(i, h) {
        rep(j, w) {
            if(table[i][j] == 1) {
                ans++;
                queue<pair<int,int>> que;
                que.emplace(i, j);
                table[i][j] = 0;

                while(!que.empty()) {
                    auto [now_i, now_j] = que.front();
                    que.pop();
                    table[now_i][now_j] = 0;
                    rep(k, 4) {
                        int nex_i = now_i + di[k];
                        int nex_j = now_j + dj[k];
                        if(nex_i >= 0 && nex_i < h && nex_j >= 0 && nex_j < w) {
                            if(table[nex_i][nex_j] == 1) {
                                que.push({nex_i, nex_j});
                                table[nex_i][nex_j] = 0;
                            }
                        }
                    }
                    int res = 0;
                    // for(auto & ii : table)for(auto & jj : ii) {
                    //     if(jj) res++;
                    // }
                    // cout << "ans : " << ans << endl;
                    // cout << "res : " << res << endl;
                }
            }
        }
    }

    cout << ans << endl;

    return 0;
}