int button = 9;
int led1 = 12;
int led2 = 11;
int led3 = 10;    
int btn = 0;   
int last = 0;   
int val = 0;     
int a;
char data;
void setup() {
  pinMode(button, INPUT); 
  pinMode(led1, OUTPUT);   
  pinMode(led2, OUTPUT);
  pinMode(led3, OUTPUT); 
  Serial.begin(9600);
}
void loop() {
  btn = digitalRead(button); 
  if (btn == HIGH && last == LOW) {
   if(val == 0){
      digitalWrite(led1 , HIGH);
      digitalWrite(led2 , LOW);
      digitalWrite(led3 , LOW);
      val=1;
   }
   else if(val==1){
      digitalWrite(led2 , HIGH);
      digitalWrite(led1 , LOW);
      digitalWrite(led3 , LOW);
    val=2;
   }
   else if(val==2){
      digitalWrite(led3 , HIGH);
      digitalWrite(led2 , LOW);
      digitalWrite(led1 , LOW);
    val=3;
   }
   else if(val==3){
      digitalWrite(led3 , HIGH);
      digitalWrite(led2 , HIGH);
      digitalWrite(led1 , HIGH);
    val=4;
   }
   else if(val==4){
      digitalWrite(led3 , LOW);
      digitalWrite(led2 , LOW);
      digitalWrite(led1 , LOW);
      val=0;
   }
    Serial.println(val);
  }
  last = btn;
  delay(50); 
}