#include <unistd.h>
#include <stdio.h>

void fast() {
  int i;
  for (i = 0; i < 2000; i++)
    printf("Doing some fast work %d\n", i);
}

void slow() {
  printf("Doing some slow non-CPU-bound work\n");
  sleep(3);
}

int main() {
  fast();
  slow();
  fast();

  return 0;
}