How do I stop scanf loop after user enters specific amount of integers?

#include <stdio.h>

int main(void) {
double numbersEntered, sum = 0;

do
{
    printf("Enter a number: ");
    scanf("%lf", &numbersEntered);
    sum += numbersEntered;
}

while (/* ??? */);

printf("Sum = %.2lf", sum);

return 0;
}

What should I do in the while statement to stop the loop after the user enters 4 integers?