program problem1(input, output);
var max, x: integer;
begin
    read(max, x);
    while x <> 0 do
        begin
            if max < x then max := x;
            read(x)
        end;
        write(max)
end.





program problem1(input, output);
var x, max: integer;
begin
    read(x);
    max := x;
    repeat
        if max < x then max := x;
        read(x)
    until x = 0;
    write(max)
end.