void setup() {
  // put your setup code here, to run once:
Serial.begin(9600);
pinMode (13, OUTPUT);
pinMode (12, OUTPUT);
pinMode (11, OUTPUT);
pinMode (10, OUTPUT);
pinMode(9, OUTPUT);
pinMode(8, OUTPUT);
pinMode(7, OUTPUT);
pinMode(6, OUTPUT);
pinMode(5, OUTPUT);

pinMode(A0, OUTPUT);
pinMode(A1, OUTPUT);
pinMode(A2, OUTPUT);
pinMode(A3, OUTPUT);

pinMode(4, INPUT_PULLUP);
pinMode(3, INPUT_PULLUP);
pinMode(2, INPUT_PULLUP);
pinMode(1, INPUT_PULLUP);


}

void loop() {
  // put your main code here, to run repeatedly:
digitalWrite(A3, LOW);
digitalWrite(A2, HIGH);
digitalWrite(A1, HIGH);
digitalWrite(A0, HIGH);

if (!digitalRead(4)){
  digitalWrite(13, HIGH);
  delay(1000);
  digitalWrite(13, LOW);
  delay(1000);

}
delay(1);

digitalWrite(A3, HIGH);
digitalWrite(A2, LOW);
digitalWrite(A1, HIGH);
digitalWrite(A0, HIGH);

if(!digitalRead(4)){
digitalWrite(12, HIGH);
delay(1000);
digitalWrite(12, LOW);
delay(1000);
}
delay(1);

digitalWrite(A3, HIGH);
digitalWrite(A2, HIGH);
digitalWrite(A1, LOW);
digitalWrite(A0, HIGH);

if(!digitalRead(4)){
digitalWrite(11, HIGH);
delay(1000);
digitalWrite(11, LOW);
delay(1000);

}
delay(1);

digitalWrite(A3, HIGH);
digitalWrite(A2, HIGH);
digitalWrite(A1, HIGH);
digitalWrite(A0, LOW);

if(!digitalRead(4)){
digitalWrite(13, HIGH);
delay(1000);
digitalWrite(13, LOW);
delay(1000);

}
delay(1);

digitalWrite(A3, LOW);
digitalWrite(A2, HIGH);
digitalWrite(A1, HIGH);
digitalWrite(A0, HIGH);

if(!digitalRead(3)){
  digitalWrite(10, HIGH);
  delay(1000);
  digitalWrite(10, LOW);
  delay(1000);
}
delay(1);

digitalWrite(A3, HIGH);
digitalWrite(A2, LOW);
digitalWrite(A1, HIGH);
digitalWrite(A0, HIGH);

if(!digitalRead(3)){
  digitalWrite(9, HIGH);
  delay(1000);
  digitalWrite(9, LOW);
  delay(1000);

}
delay(1);

digitalWrite(A3, HIGH);
digitalWrite(A2, HIGH);
digitalWrite(A1, LOW);
digitalWrite(A0, HIGH);

if(!digitalRead(3)){
  digitalWrite(8, HIGH);
  delay(1000);
  digitalWrite(8, LOW);
  delay(1000);
}
delay(1);

digitalWrite(A3, HIGH);
digitalWrite(A2, HIGH);
digitalWrite(A1, HIGH);
digitalWrite(A0, LOW);

if(!digitalRead(3)){
  digitalWrite(13, HIGH);
  delay(1000);
  digitalWrite(13, LOW);
  delay(1000);
}
delay(1);

digitalWrite(A3, LOW);
digitalWrite(A2, HIGH);
digitalWrite(A1, HIGH);
digitalWrite(A0, HIGH);

if(!digitalRead(2)){
  digitalWrite(7, HIGH);
  delay(1000);
  digitalWrite(7, LOW);
  delay(1000);

}
delay(1);

digitalWrite(A3, HIGH);
digitalWrite(A2, LOW);
digitalWrite(A1, HIGH);
digitalWrite(A0, HIGH);

if(!digitalRead(2)){
  digitalWrite(6, HIGH);
  delay(1000);
  digitalWrite(6, LOW);
  delay(1000);
}
delay(1);

digitalWrite(A3, HIGH);
digitalWrite(A2, HIGH);
digitalWrite(A1, LOW);
digitalWrite(A0, HIGH);

if(!digitalRead(2)){
  digitalWrite(5, HIGH);
  delay(1000);
  digitalWrite(5, LOW);
  delay(1000);
}
delay(1);

digitalWrite(A3, HIGH);
digitalWrite(A2, HIGH);
digitalWrite(A1, HIGH);
digitalWrite(A0, LOW);

if(!digitalRead(2)){
  digitalWrite(13, HIGH);
  delay(1000);
  digitalWrite(13, LOW);
  delay(1000);
}
delay(1);

digitalWrite(A3, LOW);
digitalWrite(A2, HIGH);
digitalWrite(A1, HIGH);
digitalWrite(A0, HIGH);

if(!digitalRead(1)){
  digitalWrite(13, HIGH);
  delay(1000);
  digitalWrite(13, LOW);
  delay(1000);

}
delay(1);

digitalWrite(A3, HIGH);
digitalWrite(A2, LOW);
digitalWrite(A1, HIGH);
digitalWrite(A0, HIGH);

if(!digitalRead(1)){
  digitalWrite(13, HIGH);
  delay(1000);
  digitalWrite(13, LOW);
  delay(1000);

}
delay(1);

digitalWrite(A3, HIGH);
digitalWrite(A2, HIGH);
digitalWrite(A1, LOW);
digitalWrite(A0, HIGH);

if(!digitalRead(1)){
  digitalWrite(13, HIGH);
  delay(1000);
  digitalWrite(13, LOW);
  delay(1000);
}
delay(1);

digitalWrite(A3, HIGH);
digitalWrite(A2, HIGH);
digitalWrite(A1, HIGH);
digitalWrite(A0, LOW);

if(!digitalRead(1)){
  digitalWrite(13, HIGH);
  delay(1000);
  digitalWrite(13, LOW);
  delay(1000);
}
delay(1);
}