#include <LiquidCrystal.h>

LiquidCrystal lcd(12, 11, 10, 9, 8, 7);

void setup() {
 lcd.begin(16, 2);
 lcd.print("Let's start!");

}

void loop() {
for (int i = 1; i<=3; i++){
  for(int j = 4; j<= 6; j++){
    boolean firstP = digitalRead(i);
    boolean secondP = digitalRead(j);
    if(!firstP && i == 1)
    lcd.print("1234");
    delay(1100);
lcd.clear();
  }
} lcd.print("Let's start!");
delay(2500);
lcd.clear();
}