int leda = 3;
int ledb = 5;
int ledc = 7;
int ledd = 9;

int btna = 2;
int btnb = 4;
int btnc = 6;
int btnd = 8;

int btnstatea = 0;
int btnstateb = 1;
int btnstatec = 0;
int btnstated = 1;

void setup() {
  // put your setup code here, to run once:
  pinMode(leda, OUTPUT);
  pinMode(ledb, OUTPUT);
  pinMode(ledc, OUTPUT);
  pinMode(ledd, OUTPUT);
  pinMode(btna, INPUT);
  pinMode(btnb, INPUT);
  pinMode(btnc, INPUT);
  pinMode(btnd, INPUT);


}

void loop() {
  // put your main code here, to run repeatedly:
  btnstatea = digitalRead(btna);
  btnstateb = digitalRead(btnb);
  btnstatec = digitalRead(btnc);
  btnstated = digitalRead(btnd);


  if (btnstatea == HIGH) {
    digitalWrite(leda, HIGH);
  }
  else {
    digitalWrite(leda, LOW);
  }

  if (btnstateb == LOW) {
    digitalWrite(ledb, LOW);
  }
  else {
    digitalWrite(ledb, HIGH);
  }

  if (btnstatec == HIGH) {
    digitalWrite(ledc, HIGH);
  }
  else {
    digitalWrite(ledc, LOW);
  }

  if (btnstated == LOW) {
    digitalWrite(ledd, LOW);
  }
  else {
    digitalWrite(ledd, HIGH);
  }


}