foo.c: In function 'main':
foo.c:5:38: warning: unused variable 'x2' [-Wunused-variable]
    5 | int a, b; int c = 0; int x1 = 0; int x2 = 0;
      |                                      ^~
foo.c:5:26: warning: unused variable 'x1' [-Wunused-variable]
    5 | int a, b; int c = 0; int x1 = 0; int x2 = 0;
      |                          ^~
foo.c:5:15: warning: unused variable 'c' [-Wunused-variable]
    5 | int a, b; int c = 0; int x1 = 0; int x2 = 0;
      |               ^

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