#include <Arduino.h> // Include the Arduino library for digitalRead() and digitalWrite()

#define LEDPIN 21

void setup() {
  Serial.begin(115200);
  pinMode(LEDPIN, OUTPUT);
  pinMode(18, INPUT);
}

void loop() {
  int s1 = digitalRead(18);
  int s2 = digitalRead(5);
  int s3 = digitalRead(19);
  int s4 = digitalRead(22);
  int s5 = digitalRead(2);
  int s6 = digitalRead(4);
  digitalWrite(LEDPIN, LOW);

  if (s1 == 1) {
    Serial.println("A");
  }
  else if (s1 == 1 && s3 == 1) {
    Serial.println("B");
  }
  else if (s1 == 1 && s2 == 1) {
    Serial.println("C");
  }
  else if (s1 == 1 && s2 == 1 && s4 == 1) {
    Serial.println("D");
  }
  else if (s1 == 1 && s4 == 1) {
    Serial.println("E");
  }
  else if (s1 == 1 && s2 == 1 && s3 == 1) {
    Serial.println("F");
  }
  else if (s1 == 1 && s2 == 1 && s3 == 1 && s4 == 1) {
    Serial.println("G");
  }
  else if (s1 == 1 && s3 == 1 && s4 == 1) {
    Serial.println("H");
  }
  else if (s3 == 1 && s2 == 1) {
    Serial.println("I");
  }
  else if (s2 == 1 && s3 == 1 && s4 == 1) {
    Serial.println("J");
  }
  else if (s1 == 1 && s5 == 1) {
    Serial.println("K");
  }
  else if (s1 == 1 && s3 == 1 && s5 == 1) {
    Serial.println("L");
  }
  else if (s1 == 1 && s2 == 1 && s5 == 1) {
    Serial.println("M");
  }
  else if (s1 == 1 && s2 == 1 && s4 == 1 && s5 == 1) {
    Serial.println("N");
  }
  else if (s1 == 1 && s4 == 1 && s5 == 1) {
    Serial.println("O");
  }
  else if (s1 == 1 && s2 == 1 && s3 == 1 && s5 == 1) {
    Serial.println("P");
  }
  else if (s1 == 1 && s2 == 1 && s3 == 1 && s4 == 1 && s5 == 1) {
    Serial.println("Q");
  }
  else if (s1 == 1 && s3 == 1 && s4 == 1 && s5 == 1) {
    Serial.println("R");
  }
  else if (s2 == 1 && s3 == 1 && s5 == 1) {
    Serial.println("S");
  }
  else if (s2 == 1 && s3 == 1 && s4 == 1 && s5 == 1) {
    Serial.println("T");
  }
  else if (s1 == 1 && s5 == 1 && s6 == 1) {
    Serial.println("U");
  }
  else if (s1 == 1 && s3 == 1 && s5 == 1 && s6 == 1) {
    Serial.println("V");
  }
  else if (s2 == 1 && s3 == 1 && s4 == 1 && s6 == 1) {
    Serial.println("W");
  }
  else if (s1 == 1 && s2 == 1 && s5 == 1 && s6 == 1) {
    Serial.println("X");
  }
  else if (s1 == 1 && s2 == 1 && s4 == 1 && s5 == 1 && s6 == 1) {
    Serial.println("Y");
  }
  else if (s1 == 1 && s4 == 1 && s5 == 1) {
    Serial.println("Z");
  }

  delay(10);
}