program masuv;
var i,n,r: integer;
m: array [1..10000] of real;
begin
writeln ('vvedit chislo');
readln (n);
for i:=1 to n do
begin
readln (m[i]);
end;
i:=1;
while (i<=n) and (m[i]<=0) do
begin
i:=i+1;
end;
if i=n+1 then
writeln ('masuv ne mistut dodatnih')
else
writeln (m[i]:2:2);
readln
end.