var b,i,sum,sq:integer;
begin
readln (b);
for i:=-10 to b do
sq:=sqr(i);
sum:=sum+sq;
end;
writeln (sum);
end.
var b,i,sum,sq:integer;
begin
readln (b);
for i:=-10 to b do
begin
sq:=sqr(i);
sum:=sum+sq;
end;
writeln (sum);
end.