foo.c: In function 'main':
foo.c:29:28: warning: unused variable 'y' [-Wunused-variable]
29 | int a,b,c,d,fz1,fm1,fz,fm,y;
| ^
foo.c: In function 'gy':
foo.c:12:1: warning: control reaches end of non-void function [-Wreturn-type]
12 | }
| ^
foo.c: In function 'gb':
foo.c:26:1: warning: control reaches end of non-void function [-Wreturn-type]
26 | }
| ^
foo.c: In function 'main':
foo.c:30:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
30 | scanf("%d%d%d%d",&a,&b,&c,&d);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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