#include <avr/io.h>
#include <avr/interrupt.h>

int main (void)
{
DDRB |= (1 << PB2);
TCCR1B|=(1 << WGM12);
OCR1A=27;
TCCR1B|=(1 << CS10);
TIMSK |= (1 << OCIE1A);
TIMSK |= (1 << OCIE1B);
sei();
while(1)
{
}}

ISR(TIMER1_COMPA_vect)
{
PORTB ^= (1<<PB2);

}