int lightpin=A5;
int lightval;
int dt=500;
int whitepin=3;
int greenpin=2;
int buzzpin=4;
void setup() {
  // put your setup code here, to run once:
pinMode(lightpin, INPUT);
pinMode(whitepin, OUTPUT);
pinMode(greenpin, OUTPUT);
Serial.begin(9600);
}

void loop() {
  // put your main code here, to run repeatedly:
lightval=analogRead(lightpin);
Serial.println(lightval);
delay(dt);

if (lightval<=20) {
digitalWrite(whitepin, HIGH);
delay(dt);
digitalWrite(whitepin, LOW);
delay(dt);
}

if (lightval>=25) {
digitalWrite(greenpin, HIGH);
delay(dt);
digitalWrite(greenpin, LOW);
delay(dt);
}
}