char key = 'q';
void setup(){
  pinMode(2, OUTPUT);
  pinMode(3, OUTPUT);
  pinMode(4, OUTPUT);
  Serial.begin(9600);
  Serial.println("exam1");
}
void loop(){
  if(Serial.available()>0){
    key = Serial.read();
  }
  if(key == 'm'){
    digitalWrite(2, LOW);
    digitalWrite(3, LOW);
    digitalWrite(4, HIGH);
    Serial.println("muhamadrusdee wo");}
  else if (key == 's'){
    digitalWrite(2, LOW);
    digitalWrite(3, HIGH);
    digitalWrite(4, LOW);
    Serial.println("saowapa 4");}
  else if (key == 't'){
    digitalWrite(2, HIGH);
    digitalWrite(3, LOW);
    digitalWrite(4, LOW);
    Serial.println("tasnim 7");}
  delay(1000);
}