program raf105;
var n,S,i: integer;
begin
readln(n);
S:= 1;
for i:=1 to n do
S:= S+5*i;
writeln(s);
end;
end.
program raf105;
var n,S,i: integer;
begin
readln(n);
S:= 1;
for i:=1 to n do
begin
S:= S+5*i;
writeln(s);
end;
end.