void setup() {
  // put your setup code here, to run once:
Serial.begin(9600);
int nilai = 90;
if (nilai < 40) {
    Serial.println("Nila: F");
  } else if (nilai >= 40 && nilai <= 50) {
    Serial.println("Nilai: E");
  } else if (nilai >= 50 && nilai <= 60) {
    Serial.println("NIlai: D");
  } else if (nilai >= 60 && nilai <= 70) {
    Serial.println("Nilai: C");
  } else if (nilai >= 70 && nilai <= 80) {
    Serial.println("Nilai: B");
  } else if (nilai >= 80 && nilai <= 90) {
    Serial.println("Nilai: A");
  } else if (nilai >= 90 && nilai <= 100) {
    Serial.println("Nilai: A+");
  }
  }

void loop() {
  // put your main code here, to run repeatedly:

}