#include <LiquidCrystal.h> // LCD kutubxonasi
const int rs = 12, en = 11, d4 = 5, d5 = 4, d6 = 3, d7 = 2;
int led = 8, kB = 6, kT = 7, count = 0;
LiquidCrystal lcd(rs, en, d4, d5, d6, d7);

void setup() {
  pinMode(led, OUTPUT); // svetadiod
  pinMode(kB, INPUT_PULLUP); // orqaga sanash
  pinMode(kT, INPUT_PULLUP); // oldinga sanash
  lcd.begin(16, 2);
}

void loop() {
  if(digitalRead(kB) != 1){
    lcd.clear();
    lcd.setCursor(0, 0);
    while(digitalRead(kB) != 1);
    lcd.print(count--);
  }
  if(digitalRead(kT) != 1){
    lcd.clear();
    lcd.setCursor(0, 0);
    while(digitalRead(kT) != 1);
    lcd.print(count++);
  }
  if(count >= 10 && count <= 20)
    digitalWrite(led, HIGH);
    else digitalWrite(led, LOW);
}