var
max,a : integer;
begin
readln(a);
max := a;
repeat
if (a > max) and (a <> 0) then
until a = 0;
writeln(max);
readln;
end.
var
max,a : integer;
begin
readln(a);
max := a;
repeat
readln(a);
if (a > max) and (a <> 0) then
max := a;
until a = 0;
writeln(max);
readln;
end.