#include <avr/io.h>

#define F_CPU 1600000
#include <util/delay.h>

void setup() { DDRB |= (1 << PB0); }

void loop() {
  while (1) {
    PORTB = PORTB ^ (1 << PORTB0);
    _delay_ms(1000);

    for (long i = 0; i < 80000; i++) {
    }
  }
}

int main() {
  setup();
  loop();
}