void setup() {
for (int i=0; i<10; i++) pinMode(i, OUTPUT);
}
void loop() { 
  for (int i=0; i<5; i++){
    switch (i) {
      case 0:
      if (digitalRead(0)==HIGH){
        digitalWrite(0, LOW);
        digitalWrite(1, LOW);
      
      }
      else {
        digitalWrite(0, HIGH);
        digitalWrite(1, HIGH);
      }
      break;
      case 1:
      if (digitalRead(2)==HIGH){
        digitalWrite(2, LOW);
        digitalWrite(3, LOW);
      }
      else {
        digitalWrite(2, HIGH);
        digitalWrite(3, HIGH);
      }
    break;
    case 2:
      if (digitalRead(4)==HIGH){
        digitalWrite(4, LOW);
        digitalWrite(5, LOW);
      }
      else {
        digitalWrite(4, HIGH);
        digitalWrite(5, HIGH);
      }
      break;
      case 3:
      if (digitalRead(6)==HIGH){
        digitalWrite(6, LOW);
        digitalWrite(7, LOW);
      }
      else {
        digitalWrite(6, HIGH);
        digitalWrite(7, HIGH);
      }
      break;
      case 4:
      if (digitalRead(8)==HIGH){
        digitalWrite(8, LOW);
        digitalWrite(9, LOW);
      }
      else {
        digitalWrite(8, HIGH);
        digitalWrite(9, HIGH);
      }
    }
  delay (300);
  }
}