void setup() {
  // put your setup code here, to run once:
pinMode(10,OUTPUT);
pinMode(8,OUTPUT);
pinMode(7,OUTPUT);

pinMode(4,INPUT_PULLUP);
pinMode(3,INPUT_PULLUP);
pinMode(2, INPUT_PULLUP);
}

void loop() {
  // put your main code here, to run repeatedly:
int sensorVal1 = digitalRead(4);
int sensorVal2 = digitalRead(3);
int sensorVal3 = digitalRead(2);

if(sensorVal1 == LOW)

{
digitalWrite(10,HIGH);
delay(400);

digitalWrite(10,LOW);
delay(400);

digitalWrite(8,HIGH);
delay(400);

digitalWrite(8,LOW);
delay(400);

digitalWrite(7,HIGH);
delay(400);

digitalWrite(7,LOW);
delay(400);
}

else if (sensorVal2 == LOW)
{
  digitalWrite(8,HIGH);
  delay(400);

  digitalWrite(8,LOW);
  delay(400);
}

else if (sensorVal3 == LOW)
{
  digitalWrite(7,HIGH);
  delay(400);

  digitalWrite(7,LOW);
  delay(400);
}

else
{
digitalWrite(10,HIGH);
digitalWrite(8,HIGH);
digitalWrite(7,HIGH);
delay(400);

digitalWrite(10,LOW);
digitalWrite(8,LOW);
digitalWrite(7,LOW);
delay(400);
}

}