void setup() {
  Serial.begin(115200);

  pinMode(8, OUTPUT);
  pinMode(7, INPUT_PULLUP);
}

int X;

void loop() {
  if(digitalRead(7) == LOW) {
    for(X = 0; X < 4; X++) {
      digitalWrite(8, HIGH);
      delay(500);
      digitalWrite(8, LOW);
      delay(500);
      Serial.print("X = ");
      Serial.println(X);
    }
  }
  Serial.print("Input 7 = ");
  Serial.println(digitalRead(7));
  delay(100);
}