#include <bits/stdc++.h>
using namespace std;
using ll = long long;

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    int h, w, ans = 0, v;
    cin >> h >> w;
    vector<vector<bool>> A(h, vector<bool>(w)), B(h, vector<bool>(w));
    for(int y = 0; y < h; y++){
        for(int x = 0; x < w; x++){
            cin >> v;
            A[y][x] = v;
        }
    }
    queue<pair<int,int>> nxt;
    for(int cy = 0; cy < h; cy++){
        for(int cx = 0; cx < w; cx++){
            if(B[cy][cx])continue;
            if(!A[cy][cx])continue;
            ans++;
            B[cy][cx] = true;
            nxt.emplace(cy, cx);
            while(!nxt.empty()){
                int y, x;
                tie(y, x) = nxt.front();
                nxt.pop();
                for(int i = 0; i < 4; i++){
                    int ny = y + (i == 0) - (i == 1);
                    int nx = x + (i == 2) - (i == 3);
                    if(ny < 0 || nx < 0 || ny >= h || nx >= w)continue;
                    if(B[ny][nx])continue;
                    if(A[ny][nx] ^ A[y][x])continue;
                    B[ny][nx] = true;
                    nxt.emplace(ny, nx);
                }
            }
        }
    }
    cout << ans << '\n';
}