#include <stdio.h>

int main(int argc, char **argv) {
  FILE *f1 = fopen("hello.txt", "w");
  printf("%x\n", (unsigned int) f1);
  FILE *f2 = fopen("hello.txt", "r");
  printf("%x\n", (unsigned int) f2);
  FILE *f3 = fopen("hello.txt", "w");
  printf("%x\n", (unsigned int) f3);
}