#define RED_LED 3
#define GREEN_LED 5

int8_t RED = 0;
int8_t GREEN = 127;


void setup() {
  pinMode(RED_LED, OUTPUT);
  pinMode(GREEN_LED, OUTPUT);
}

void loop() {
  analogWrite(RED_LED, abs(RED));
  analogWrite(GREEN_LED, abs(GREEN));

  RED++;
  GREEN++;

  delay(10);
}