#include <LiquidCrystal.h>

int in = 15; 
int inpr = 16; 
int out = 14; 
int outpr = 17; 
int ppl = 0;
LiquidCrystallcd(12, 11, 5, 4, 3, 2);
bool pi = 0;
bool po = 0;
void setup() {
pinMode(15, INPUT);
pinMode(14, INPUT);
pinMode(16, OUTPUT);
pinMode(17, OUTPUT);
lcd.begin(16, 2);
}

void loop() {
lcd.clear();
digitalWrite(outpr, HIGH);
digitalWrite(inpr, HIGH);
pi = digitalRead(in);
po = digitalRead(out);
if (pi == 1){
ppl--;
delay(500);
}
else if (po == 1){
ppl++ ;
delay(500);
}
ppl = constrain(ppl, 0, 50);
lcd.setCursor(0, 0);

lcd.print("PEOPLE IN:");
lcd.setCursor(11, 0);
lcd.print(ppl);
if (ppl >= 20){
lcd.setCursor(0, 1);
lcd.print("PLEASE WAIT");
delay(1000);
}
if (ppl <= 19){
lcd.setCursor(0, 1);
lcd.print("PLEASE VISIT");
delay(1000);
}
}