#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x27,16,2);
int switch1 = 7;
int switch2 = 6;
int switch3 = 5;
int switch4 = 4;
int led = 12;
String a;
void setup() {
  Serial.begin(9600);
  lcd.init();
  lcd.backlight();
  pinMode(switch1, INPUT);
  pinMode(switch2, INPUT);
  pinMode(switch3, INPUT);
  pinMode(switch4, INPUT);
  pinMode(led, OUTPUT);
  // put your setup code here, to run once:

}

void loop() {
  int push1 = digitalRead(switch1);
  int push2 = digitalRead(switch2);
  int push3 = digitalRead(switch3);
  int push4 = digitalRead(switch4);
  if (push1 == 1)
  {
    a += "O";
    delay(1000);
  }
  if (push2 == 1)
  {
    a += "P";
    delay(1000);
  }
  if (push3 == 1)
  {
    a += "E";
    delay(1000);
  }
  if (push4 == 1)
  {
    a += "N";
    delay(1000);
  }
  if (a.length() >= 4)
  {
    if (a == "OPEN")
    {
      digitalWrite(led, HIGH);
      lcd.setCursor(0,0);
      lcd.print("opened");
      Serial.println(a);
      delay(10000);
      digitalWrite(led, LOW);
      delay(10000);
    }
    else 
    {
      digitalWrite(led, LOW);
      lcd.setCursor(0,0);
      lcd.print("closed");
      delay(1000);
      Serial.println("wrong password");
    }
  }
  // put your main code here, to run repeatedly:

}