#include <LiquidCrystal.h>
const int rs=12, en=11, d4=5, d5=4, d6=3, d7=2;
LiquidCrystal lcd(rs,en,d4,d5,d6,d7);
int in = 8 , out = 9 , in_value = 0 , out_value = 0 , remain;
void setup() {
  lcd.begin(16,2);
  pinMode(in , INPUT);
  pinMode(out , INPUT);
}
void loop() {
  lcd.clear();
  in_value = in_value + digitalRead(in);
  out_value = out_value + digitalRead(out);
  remain = in_value - out_value;
  if(in_value==out_value){
    in_value=0 , out_value=0 , remain=0;
  }
  lcd.setCursor(0,0);
  lcd.print("IN  OUT   REMAIN");
  lcd.setCursor(0,1);
  lcd.print(in_value);
  lcd.setCursor(5,1);
  lcd.print(out_value);
  lcd.setCursor(12,1);
  lcd.print(remain);
  delay(100);
}