void setup() {
  // put your setup code here, to run once:
  pinMode(PA3, INPUT);
  pinMode(PA7, OUTPUT);


delay(5000);

}

void loop() {
  
  // put your main code here, to run repeatedly:
if(digitalRead(PA3))
{
digitalWrite(PA7,HIGH);
delay(1000);
digitalWrite(PA7,LOW);
delay(1000);
digitalWrite(PA7,HIGH);
delay(1000);


digitalWrite(PA7,LOW);
delay(1000);
digitalWrite(PA7,HIGH);
delay(1000);


digitalWrite(PA7,LOW);
delay(1000);
digitalWrite(PA7,HIGH);
delay(1000);

}
  

}