// file: stack-ex.c
#include <stdio.h>
#include <stdlib.h>

long leaf(long z) {
    return z + 2;
}

long top(long x) {
    long y = x - 5;
    long z = leaf(y);
    z *= 2;
    return z;
}

int main(int argc, char **argv)
{
    long result = top(100);    
    printf("result: %lu\n", result);
    return 0;
}