#include <LiquidCrystal.h>
LiquidCrystal lcd(13,12,11,10,9,8);
int count;
#define I 7

void setup() {
lcd.begin(16,2);
DDRD &= ~(1<<3);
PORTD |= (1<<3);
EICRA |= 1<<ISC11;
EICRA &= ~(1<<ISC10);
EIMSK |= 1<<INT1;
SREG |= 1<<7;

SREG |= 1<<I;
PCICR |= 1<<PCIE2;
PCICR |= 1<<PCIE1;
PCMSK2 |= 1<<PCINT23;
PCMSK2 |= 1<<PCINT21;
PCMSK1 |= 1<<PCINT13;
}

void loop() {
lcd.clear();
lcd.println("Waiting");
lcd.setCursor(0,1);
lcd.print("Players: ");
lcd.print(count);
delay(200);
lcd.home();
lcd.println("Waiting.");
delay(200);
lcd.home();
lcd.println("Waiting..");
delay(200);
lcd.home();
lcd.println("Waiting...");
delay(200);
}

ISR(PCINT2_vect)
{
  if((PIND&(1<<7)) == 0)
  {
    count++;
    lcd.setCursor(9,1);
    lcd.print(count);
  }

  if((PIND&(1<<5)) == 0)
  {
    count--;
    lcd.setCursor(9,1);
    lcd.print(count);
  }
}

ISR(PCINT1_vect)
{
  count = 0;
  lcd.setCursor(9,1);
  lcd.print(count);
}