var a:integer;
begin
readln(a);
if (a<0) then a:=a*(-1) else a:=0;
writeln(a);
end.
Program zadacha;
var x:integer;
Begin
readln(x);
if (x<0) then a:=abs(x)
else a:=0;
writeln(x);
var a:integer;
begin
readln(a);
if (a<0) then a:=a*(-1) else a:=0;
writeln(a);
end.
Program zadacha;
var x:integer;
Begin
readln(x);
if (x<0) then a:=abs(x)
else a:=0;
writeln(x);
end.