int LDR;
void setup() {
  // put your setup code here, to run once:
Serial.begin(9600);
pinMode(3,OUTPUT);
pinMode(4,OUTPUT);
pinMode(5,OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
LDR=analogRead(A3);
Serial.println(LDR);
Serial.print("LDR  = ");
delay(500);
if(LDR<=150){
digitalWrite(3,1);
digitalWrite(4,0);
digitalWrite(5,0);
}
else if(LDR>=300){
digitalWrite(3,0);
digitalWrite(4,1);
digitalWrite(5,0);
}
else {
digitalWrite(3,0);
digitalWrite(4,0);
digitalWrite(5,1);
}
}