int ledr1=4;
int ledr2=5;
int ledg1=6;
int ledg2=7;
void setup()
{
 pinMode(ledr1, OUTPUT);
 pinMode(ledr2, OUTPUT);
 pinMode(ledg1, OUTPUT);
 pinMode(ledg2, OUTPUT);
 }
void loop()
{
digitalWrite(ledr1, HIGH);
digitalWrite(ledr2, HIGH);
digitalWrite(ledg1, LOW);
digitalWrite(ledg2, LOW);
delay (1000);
digitalWrite(ledg1, HIGH);
digitalWrite(ledg2, HIGH);
digitalWrite(ledr1, LOW);
digitalWrite(ledr2, LOW);
delay (1000);
digitalWrite(ledr1, HIGH);
delay (1000);
digitalWrite(ledg1, HIGH);
delay (1000);
digitalWrite(ledr2, LOW);
delay (1000);
digitalWrite(ledg2, LOW);
delay (1000);
digitalWrite(ledg1, LOW);
digitalWrite(ledg2, LOW);
digitalWrite(ledr1, LOW);
digitalWrite(ledr2, LOW);
delay (1000);
}