GATE 2018 CS – Question 31

Consider the following C program:

#include <stdio.h>

int counter = 0;

int calc (int a, int b) {
    int c;

    counter++;
    if (b==3) return (a*a*a);
    else {
        c = calc(a, b/3);
        return (c*c*c);
    }
}

int main () {
    calc(4, 81);
    printf ("%d", counter);
}

The output of this program is ________.