foo.c: In function 'main':
foo.c:15:5: warning: this 'else' clause does not guard... [-Wmisleading-indentation]
   15 |     else
      |     ^~~~
foo.c:19:9: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'else'
   19 |         return 0;
      |         ^~~~~~
foo.c:4:16: warning: variable 'b' set but not used [-Wunused-but-set-variable]
    4 |         int a, b;
      |                ^

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