#include <stdio.h>
bool f[3002][3002]={0};
int h,w;

void check(short i,short j){
    if (!f[i][j])return;
    f[i][j]=false;
    check(i-1,j);
    check(i+1,j);
    check(i,j-1);
    check(i,j+1);
}
int main() {
    scanf("%d %d", &h, &w);
    for (short i=1;i<=h;i++) {
        for (short j=1;j<=w;j++) {
            scanf("%d", &f[i][j]);
        }
    }
    
    int ans=0;
    for (short i=1;i<=h;i++) {
        for (short j=1;j<=w;j++) {
            if (f[i][j]) {
                check(i,j);
                ++ans;
            }
        }
    }
    printf("%d\n",ans);
    return 0;
}