var
CH, CH1: INTEGER;
begin
writeln('Введите число');
readln(CH);
CH1 := 1;
while CH1 < CH do
begin
CH1 := CH1 * 3;
end;
if CH1 = CH then
writeln('YES')
else
writeln('NO');
end.
var
CH, CH1: INTEGER;
begin
writeln('Введите число');
readln(CH);
CH1 := 1;
while CH1 < CH do
begin
CH1 := CH1 * 3;
end;
if CH1 = CH then
writeln('YES')
else
writeln('NO');
end.