foo.c: In function 'ss':
foo.c:5:8: warning: unused variable 'n' [-Wunused-variable]
  int m,n;
        ^
foo.c: In function 'main':
foo.c:17:10: warning: unused variable 'c' [-Wunused-variable]
  int a,b,c,x;
          ^
foo.c:17:8: warning: unused variable 'b' [-Wunused-variable]
  int a,b,c,x;
        ^
foo.c: In function 'ss':
foo.c:14:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^
foo.c: In function 'main':
foo.c:18:5: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d",&x);
     ^~~~~~~~~~~~~~

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