foo.c: In function 'main':
foo.c:6:17: warning: format '%d' expects argument of type 'int *', but argument 2 has type 'int' [-Wformat=]
    6 |         scanf("%d %d\n %d %d",a1,x1,a2,x2);
      |                ~^             ~~
      |                 |             |
      |                 int *         int
foo.c:6:20: warning: format '%d' expects argument of type 'int *', but argument 3 has type 'int' [-Wformat=]
    6 |         scanf("%d %d\n %d %d",a1,x1,a2,x2);
      |                   ~^             ~~
      |                    |             |
      |                    int *         int
foo.c:6:25: warning: format '%d' expects argument of type 'int *', but argument 4 has type 'int' [-Wformat=]
    6 |         scanf("%d %d\n %d %d",a1,x1,a2,x2);
      |                        ~^           ~~
      |                         |           |
      |                         int *       int
foo.c:6:28: warning: format '%d' expects argument of type 'int *', but argument 5 has type 'int' [-Wformat=]
    6 |         scanf("%d %d\n %d %d",a1,x1,a2,x2);
      |                           ~^           ~~
      |                            |           |
      |                            int *       int
foo.c:6:9: warning: 'a1' is used uninitialized [-Wuninitialized]
    6 |         scanf("%d %d\n %d %d",a1,x1,a2,x2);
      |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
foo.c:5:13: note: 'a1' was declared here
    5 |         int a1,x1,a2,x2;
      |             ^~
foo.c:6:9: warning: 'x1' is used uninitialized [-Wuninitialized]
    6 |         scanf("%d %d\n %d %d",a1,x1,a2,x2);
      |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
foo.c:5:16: note: 'x1' was declared here
    5 |         int a1,x1,a2,x2;
      |                ^~
foo.c:6:9: warning: 'a2' is used uninitialized [-Wuninitialized]
    6 |         scanf("%d %d\n %d %d",a1,x1,a2,x2);
      |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
foo.c:5:19: note: 'a2' was declared here
    5 |         int a1,x1,a2,x2;
      |                   ^~
foo.c:6:9: warning: 'x2' is used uninitialized [-Wuninitialized]
    6 |         scanf("%d %d\n %d %d",a1,x1,a2,x2);
      |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
foo.c:5:22: note: 'x2' was declared here
    5 |         int a1,x1,a2,x2;
      |                      ^~

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