// URL: https://yukicoder.me/problems/no/697

import std.algorithm, std.array, std.container, std.math, std.range, std.typecons, std.string;
import std.bitmanip;

version(unittest) {} else
void main()
{
  int H, W; io.getV(H, W);
  auto n = (H+2)*(W+2);

  auto b = BitArray();
  b.length = n;

  foreach (r; 0..H) {
    int[] A; io.getA(W, A);
    foreach (c; 0..W)
      if (A[c]) b[(r+1)*(W+2)+c+1] = true;
  }

  auto v = BitArray();
  v.length = n;

  auto p = 0;
  foreach (i; 0..n) {
    if (b[i] && !v[i]) {
      ++p;
      auto q = DList!int(i);
      v[i] = true;
      while (!q.empty) {
        auto d = q.front; q.removeFront();
        foreach (e; [d-1, d+1, d-(W+2), d+(W+2)]) {
          if (b[e] && !v[e]) {
            v[e] = true;
            q.insertBack(e);
          }
        }
      }
    }
  }

  io.put(p);
}

auto io = IO!()();
import std.stdio;
struct IO(string floatFormat = "%.10f", string delimiter = " ", alias IN = stdin, alias OUT = stdout)
{
  import std.conv, std.format, std.meta, std.traits;

  auto getV(T...)(ref T v) { foreach (ref w; v) get(w); }
  auto getA(T)(size_t n, ref T v) if (hasAssignableElements!T)
  { v = new T(n); foreach (ref w; v) get(w); }
  auto getC(T...)(size_t n, ref T v)
  if (allSatisfy!(hasAssignableElements, T))
  {
    foreach (ref w; v) w = new typeof(w)(n);
    foreach (i; 0..n) foreach (ref w; v) get(w[i]);
  }
  auto getM(T)(size_t r, size_t c, ref T v)
  if (hasAssignableElements!T && hasAssignableElements!(ElementType!T))
  {
    v = new T(r); foreach (ref w; v) getA(c, w);
  }
  template getS(E...)
  {
    auto getS(T)(size_t n, ref T v)
    {
      v = new T(n); foreach (ref w; v) foreach (e; E) mixin("get(w."~e~");");
    }
  }

  auto put(bool flush = false, T...)(T v)
  {
    foreach (i, w; v) { putA(w); if (i < v.length-1) OUT.write(delimiter); }
    OUT.writeln;
    static if (flush) OUT.flush();
  }
  auto putB(S, T)(bool c, S t, T f) { if (c) put(t); else put(f); }
  auto putRaw(T...)(T v) { OUT.write(v); OUT.writeln; }

  private
  {
    dchar[] buf;
    auto sp = (new dchar[](0)).splitter;
    void nextLine() { IN.readln(buf); sp = buf.splitter; }
    auto get(T)(ref T v) { if (sp.empty) nextLine(); v = sp.front.to!T; sp.popFront(); }

    auto putR(T)(T v)
    {
      auto w = v;
      while (!w.empty) { putA(w.front); w.popFront(); if (!w.empty) OUT.write(delimiter); }
    }
    auto putA(T)(T v)
    {
      static if (isInputRange!T && !isSomeString!T) putR(v);
      else if (isFloatingPoint!T) OUT.write(format(floatFormat, v));
      else OUT.write(v);
    }
  }
}