const
    MAXN = 10000;
    MAXL = 64;
type matrix = array[0..MAXN-1] of array[0..MAXL-1] of char;

function invalid(N: longint; var U: matrix): longint;
begin
    (* insert your code here *)
    invalid := 42;
end;


var
    N, i  : longint;
    U     : matrix;
    fr, fw: text;

begin
    assign(fr, 'input.txt');
    assign(fw, 'output.txt');
    reset(fr);
    rewrite(fw);
    readln(fr, N);
    for i:=0 to N-1 do
        readln(fr, U[i]);

    writeln(fw, invalid(N, U));
    close(fr);
    close(fw);
end.