#include <cstdio>
#include <iostream>
#include <fstream>
#include <vector>
#include <list>
#include <map>
#include <set>
#include <queue>
#include <stack>
#include <bitset>
#include <algorithm>
#include <sstream>
#include <iomanip>
#include <cmath>
#include <cstdlib>
#include <cctype>
#include <cstring>
#include <string>
#include <ctime>
#include <cassert>
#include <utility>

using namespace std;

#define MAXN 550
#define INF 100000000

int N, M;
char S[MAXN];
int A[MAXN][MAXN];
int idx[MAXN][MAXN];
int low[MAXN][MAXN];
int ans, crtIdx;

int di[] = { 0, 1, 0, -1 };
int dj[] = { 1, 0, -1, 0 };

void dfs(int pi, int pj, int prev) {
    idx[pi][pj] = ++crtIdx;
    low[pi][pj] = INF;
    for(int d = 0; d < 4; d++) {
        int ni = pi + di[d];
        int nj = pj + dj[d];
        if(ni >= 0 && ni < N && nj >= 0 && nj < M && A[ni][nj] == 1 && idx[ni][nj] != prev) {
            if(idx[ni][nj] == 0) {
                dfs(ni, nj, idx[pi][pj]);
                low[pi][pj] = min(low[pi][pj], low[ni][nj]);
            }
            else
                low[pi][pj] = min(low[pi][pj], idx[ni][nj]);
        }
    }
    if(low[pi][pj] <= idx[pi][pj])
        ans++;
}

int main() {
//	freopen("date.in", "r", stdin);
//	freopen("date.out","w", stdout);
	
	scanf("%d %d\n", &N, &M);
	for(int i = 0; i < N; i++) {
        fgets(S, sizeof(S), stdin);
        for(int j = 0; j < M; j++)
            A[i][j] = (S[j] == '1');
	}
	
	crtIdx = 0;
	ans = 0;
	for(int i = 0; i < N; i++)
        for(int j = 0; j < M; j++)
            if(idx[i][j] == 0 && A[i][j] == 1)
                dfs(i, j, -1);
	
	printf("%d\n", ans);
	
	return 0;
}