int redLed=2;
int yellowLed=3;
int greenLed=4;
int redKey=5;
int yellowKey=6;
int greenKey=7;
int resetKey=8;
void setup() {
  // put your setup code here, to run once:
pinMode(redLed, OUTPUT);
pinMode(yellowLed, OUTPUT);
pinMode(greenLed, OUTPUT);
pinMode(redKey, INPUT_PULLUP);
pinMode(yellowKey, INPUT_PULLUP);
pinMode(greenKey, INPUT_PULLUP);
pinMode(resetKey, INPUT_PULLUP);

}

void loop() {
  // put your main code here, to run repeatedly:
if(digitalRead(redKey)==LOW)
RED();
if(digitalRead(yellowKey)==LOW)
YELLOW();
if(digitalRead(greenKey)==LOW)
GREEN();
}
void RED()
{
  while(digitalRead(resetKey)==1)
  {
    digitalWrite(redLed, HIGH);
    digitalWrite(yellowLed,LOW);
    digitalWrite(greenLed, LOW);
  }
 clear();
}
void YELLOW()
  {while(digitalRead(resetKey)==1)
  {
    digitalWrite(redLed, LOW);
    digitalWrite(yellowLed, HIGH);
    digitalWrite(greenLed, LOW);
  }
  clear();

}
void GREEN()
  {while(digitalRead(resetKey)==1)
  {
    digitalWrite(redLed, LOW);
    digitalWrite(yellowLed, LOW);
    digitalWrite(greenLed, HIGH);
  }
  clear();
  
}
void clear(){
  digitalWrite(redLed, LOW);
    digitalWrite(yellowLed, LOW);
    digitalWrite(greenLed, LOW);
}