foo.c: In function 'main':
foo.c:5:30: warning: variable 'y' set but not used [-Wunused-but-set-variable]
    5 |         int a=15,b=18,c=21,x,y;
      |                              ^
foo.c:5:28: warning: variable 'x' set but not used [-Wunused-but-set-variable]
    5 |         int a=15,b=18,c=21,x,y;
      |                            ^

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