const int LEDR =25;
const int LEDY =26;
const int LEDG =27;



void setup() 
{ 
  pinMode(LEDR, OUTPUT); 
  pinMode(LEDY, OUTPUT); 
  pinMode(LEDG, OUTPUT); 
} 
void loop() 
{ 
  digitalWrite(LEDR, HIGH); 
  digitalWrite(LEDY, LOW); 
  digitalWrite(LEDG, LOW); 
  delay(1000);  
  digitalWrite(LEDR, LOW); 
  digitalWrite(LEDY, HIGH); 
  digitalWrite(LEDG, LOW); 
  delay(1000); 
  digitalWrite(LEDR, LOW); 
  digitalWrite(LEDY, LOW); 
  digitalWrite(LEDG, HIGH); 
  delay(1000); 
}