foo.c: In function 'main':
foo.c:5:10: warning: format '%d' expects argument of type 'int *', but argument 2 has type 'long unsigned int *' [-Wformat=]
  scanf("%d %d",&x1,&x2);
          ^
foo.c:5:13: warning: format '%d' expects argument of type 'int *', but argument 3 has type 'long unsigned int *' [-Wformat=]
  scanf("%d %d",&x1,&x2);
             ^

自豪的采用jd5进行评测(github.com/masnn/jd5)