foo.c: In function 'main':
foo.c:6:19: warning: format '%d' expects argument of type 'int *', but argument 3 has type 'int' [-Wformat=]
    6 |         scanf("%d%d",&x1,x2);
      |                  ~^      ~~
      |                   |      |
      |                   int *  int
foo.c:6:9: warning: 'x2' is used uninitialized [-Wuninitialized]
    6 |         scanf("%d%d",&x1,x2);
      |         ^~~~~~~~~~~~~~~~~~~~
foo.c:5:12: note: 'x2' was declared here
    5 |     int x1,x2;
      |            ^~

[Hydro](https://hydro.ac)提供评测服务