//na                            :cuixiaofei;
//da                            :08_11_11;
program crane;
  var
    n,m                         :longint;
    a                           :array[1..100,1..100] of longint;
    f1,f2                       :text;
  procedure init;
    var
      i,j                       :longint;
  begin
    assign(f1,'arcane.in');
    reset(f1);
    assign(f2,'arcane.out');
    rewrite(f2);
    readln(f1,n,m);
    for i:=1 to n do
      for j:=1 to m do
        read(f1,a[i,j]);
  end;
  procedure diao;
  begin
    close(f1);
    close(f2);
  end;
  procedure print;
    var
      i,j,ge                    :longint;
  begin
    ge:=0;
    for i:=1 to n do
      for j:=1 to m do
        if a[i,j]=0 then
          inc(ge);
    if ge>=n*m div 2 then
      begin
        writeln(f2,0);
        diao;
        halt;
      end;
    ge:=0;
    for i:=1 to n do
      for j:=1 to m do
        if a[i,j]=15 then
          inc(ge);
    if ge>=(n*m) div 2 then
      begin
        writeln(f2,1);
        diao;
        halt;
      end;
    if (n<5) and (m<5) then
      writeln(f2,2)
    else if (n<25) and (m<25) then
      writeln(f2,10)
    else
      writeln(f2,1);
    diao;
  end;
  begin
    init;
    print;
  end.