foo.c: In function 'hj1':
foo.c:21:17: warning: variable 'fm' set but not used [-Wunused-but-set-variable]
   21 |  int fz1,fm1,fz,fm;
      |                 ^~
foo.c: In function 'hj2':
foo.c:30:14: warning: variable 'fz' set but not used [-Wunused-but-set-variable]
   30 |  int fz1,fm1,fz,fm;
      |              ^~
foo.c: In function 'main':
foo.c:39:19: warning: unused variable 'fm' [-Wunused-variable]
   39 |  int a,b,c,d,n,fz,fm,t;
      |                   ^~
foo.c:39:16: warning: unused variable 'fz' [-Wunused-variable]
   39 |  int a,b,c,d,n,fz,fm,t;
      |                ^~
foo.c: In function 'gy':
foo.c:12:1: warning: control reaches end of non-void function [-Wreturn-type]
   12 | }
      | ^
foo.c: In function 'main':
foo.c:40:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   40 |  scanf("%d",&n);
      |  ^~~~~~~~~~~~~~
foo.c:44:4: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   44 |    scanf("%d%d",&a,&b);
      |    ^~~~~~~~~~~~~~~~~~~
foo.c:47:4: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   47 |    scanf("%d%d",&c,&d);
      |    ^~~~~~~~~~~~~~~~~~~

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