#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x27, 16, 2);
int red = 9;
int yellow = 8;
int green = 7;
float timeLeft;



void setup(){
  pinMode(red, OUTPUT);
  pinMode(yellow, OUTPUT);
  pinMode(green,  OUTPUT);
  lcd.begin(16, 2);
}

void loop(){
 digitalWrite(red, HIGH);
 timeLeft = 10;
 while (timeLeft --)
 {
  lcd.clear();
  lcd.setCursor(0,0);
  lcd.print(timeLeft);
  delay(1000);
 }
 digitalWrite(red,  LOW);
 digitalWrite(yellow, HIGH);
 timeLeft = 3;
 while (timeLeft --)
 {
  lcd.clear();
  lcd.setCursor(0,0);
  lcd.print(timeLeft);
  delay(1000);
 }
 digitalWrite(yellow,  LOW);
 digitalWrite(green, HIGH);
 timeLeft = 15;
 while (timeLeft --)
 {
  lcd.clear();
  lcd.setCursor(0,0);
  lcd.print(timeLeft);
  delay(1000);
 }
 digitalWrite(green,  LOW);
}