#include <LiquidCrystal.h>
const int rs = 12, en = 11, d4 = 9, d5 = 8, d6 = 7, d7 = 6;
 LiquidCrystal lcd(rs, en, d4, d5, d6, d7);
int btn=3;
void setup() {
  // set up the LCD's number of columns and rows:
    lcd.begin(16, 2);
  Serial.begin(9600);
      // Print a message to the LCD.
      lcd.setCursor(0,0);
        lcd.print("Hello all guy");
        lcd.setCursor(1,2);
        lcd.print("welcome");
        delay(1000);
        lcd.clear();
        lcd.print (" to day no class");
        lcd.setCursor(2,1);
        lcd.print("but have homework");
        pinMode(btn, INPUT);
        if(btn==HIGH){
          lcd.setCursor(3,1);
    lcd.print("btn read:");
    delay(1000);

lcd.print("%d");
    lcd.clear();
        }
    }
        void loop() {
          // set the cursor to column 0, line 1
            // (note: line 1 is the second row, since counting begins with 0):
            
                  }