int led_re=7;
int led_or=6;
int led_gr=5;

int delay_re=10000;
int delay_or=2000;
int delay_gr=5000;

void setup()
{
for(int i=led_gr;i<=led_re;i++)
pinMode(i, OUTPUT);
}
void loop()
{
digitalWrite(led_or,LOW);
digitalWrite(led_re,HIGH);
delay(delay_re);

digitalWrite(led_re,LOW);
digitalWrite(led_gr,HIGH);
delay(delay_gr);

digitalWrite(led_gr,LOW);
digitalWrite(led_or,HIGH);
delay(delay_or);
}