#include <LiquidCrystal_I2C.h>
#define ledRed 8
#define ledYellow 9
#define ledGreen 7
#define BUZZER_PIN 10
LiquidCrystal_I2C lcd(0x27, 16, 2);
float timeLeft;
void setup() {
pinMode(ledRed, OUTPUT);
pinMode(ledYellow, OUTPUT);
pinMode(ledGreen, OUTPUT);
pinMode(BUZZER_PIN, OUTPUT);
lcd.begin(16, 2);
}
void loop() {
 digitalWrite(ledYellow, HIGH);
 timeLeft = 10;
 while ( timeLeft-- )
 {
    lcd.clear();
    lcd.println(timeLeft);
    delay(1000);
 }
 digitalWrite(ledYellow, LOW);
 digitalWrite(ledRed, HIGH);
 timeLeft = 3;
 while ( timeLeft-- )
 {
    lcd.clear();
    lcd.println(timeLeft);
    delay(1000);
 }
 digitalWrite(ledRed, LOW);
 digitalWrite(ledGreen, HIGH);
 timeLeft = 15;
 while ( timeLeft-- )
 {
    lcd.clear();
    lcd.println(timeLeft);
    delay(1000);
 }
 digitalWrite(ledGreen, LOW);
 digitalWrite(ledRed, HIGH);
 timeLeft = 3;
 while ( timeLeft-- )
 {
    lcd.clear();
    lcd.println(timeLeft);
    delay(1000);
 }
 digitalWrite(ledRed, LOW);
}