int H,W;
int iso = 0;
int A[3002][3002];

void dfs(int y, int x){
    if (A[y][x] == 0) return;
    A[y][x] = 0; --iso;
    dfs(y, x-1);
    dfs(y, x+1);
    dfs(y-1, x);
    dfs(y+1, x);
}

{
    rd(H,W);
    REP(y,1,H+1) REP(x,1,W+1) rd(A[y][x]), iso += A[y][x];
    REP(y,1,H+1) REP(x,1,W+1) if (A[y][x] == 1){ ++iso; dfs(y,x); }
    wt(iso);
}