program graf;
var n,m:int64;
     f,g:text;
     a:array[1..1000,1..1000] of byte;
procedure citire;
var i,j,k:longint;
begin
  assign(f,'dfs.in');
  assign(g,'dfs.out');
  reset(f);
  rewrite(g);
  readln(f,n,m);
 { for k:=1 to m do
    begin
      readln(f,i,j);
      a[i,j]:=1;
      a[j,i]:=1;
    end;}
  close(f);
end;
begin
  citire;
  writeln(g,n-m);
  close(g);
end.