const int LED_PINS[] ={13,10,7,4};
const int buttonpin[] ={3};

//int Buttonstate = LOW;

void setup() {
pinMode(LED_PINS[0], OUTPUT);
pinMode(LED_PINS[1], OUTPUT);
pinMode(LED_PINS[2], OUTPUT);
pinMode(LED_PINS[3], OUTPUT);
pinMode(buttonpin[0], INPUT);
 
}

void loop() {
 
 int Buttonstate = digitalRead(buttonpin[0]);

 if (Buttonstate == LOW) 
 {
digitalWrite(LED_PINS[0], HIGH);
delay(1000);
digitalWrite(LED_PINS[0], LOW);

digitalWrite(LED_PINS[1], HIGH);
delay(1000);
digitalWrite(LED_PINS[1], LOW);
}
else
{
digitalWrite(LED_PINS[2], HIGH);
delay(1000);
digitalWrite(LED_PINS[2], LOW);

digitalWrite(LED_PINS[3], HIGH);
delay(1000);
digitalWrite(LED_PINS[3], LOW);
}

}