void setup() {
  // put your setup code here, to run once:
pinMode(7, INPUT);
pinMode(8, OUTPUT);
pinMode(9, OUTPUT);
pinMode(10, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
digitalWrite(8, HIGH);
delay(200);
while(digitalRead(7)==HIGH){
  delay(1000);
}
digitalWrite(8, LOW);
digitalWrite(9, HIGH);
delay(200);
while(digitalRead(7)==HIGH){
  delay(1000);

}
digitalWrite(9, LOW);
delay(200);
digitalWrite(10, HIGH);
delay(200);
while(digitalRead(7)==HIGH){
  delay(1000);
}
digitalWrite(10, LOW);
}