// Pantea Aria


// You're at an ATM. 
// It asks you to enter your 4-digit PIN. 
// If it's wrong, it asks again — 
// and it will keep asking until you enter the correct one

// am I repeating anything? yes -> loop -> while -> how many times -> we don't know
// if pin is correct you stop
// true or false
// if pin is false I should repeating// pin in this question is called a sentinel value
// imagine the correct PIN is 1234

#include <stdio.h>

#define PIN 1234

int main(void) {

    int stop = 0;
    int pin;
    while (stop != 1) {
        printf ("Enter your pin:");
        scanf ("%d", &pin);

        if (pin == PIN) {
            stop = 1;
        }

    }

    
    return 0;
}