#include <iostream>
#include <cstdlib>

typedef struct circle_st {
  int area;
} Circle;

void CylinderVolume(const Circle &face, int height, int *const volume) {
  *volume = face.area * height;
}

int main(int argc, char **argv) {
  Circle circ;
  circ.area = 20;
  int height = 30;
  int volume;

  CylinderVolume(circ, height, &volume);
  return EXIT_SUCCESS;
}