#include <Wire.h>
#include <LiquidCrystal_I2C.h>
int z = 0;
int l = 0;
LiquidCrystal_I2C lcd(0x27,20,4);
void setup() {
  lcd.begin(20,4);
  lcd.init();
  lcd.backlight();
pinMode(A0, INPUT_PULLUP);
pinMode(0, INPUT_PULLUP);
}


void loop() {
  int z = analogRead(A0);
if( digitalRead(0) == 0){delay(100);  l++;}
else if (l> 1){l = 0;}

if(l==0){

z =map(z,0,1023,0,100);
lcd.clear();
lcd.setCursor(0,0);
lcd.print("vr=");
lcd.print(z);
 delay(200);}
 
 else if (l==1){
 
z =map(z,0,1023,0,100);
lcd.clear();
lcd.setCursor(0,1);
lcd.print("vr2=");
lcd.print(z);
 delay(200);}
 }