foo.c: In function 'main':
foo.c:6:20: warning: unused variable 'deno' [-Wunused-variable]
     int rank,i,n,m,deno;
                    ^~~~
foo.c:7:5: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d",&rank);
     ^~~~~~~~~~~~~~~~~
foo.c:20:13: warning: 'all' may be used uninitialized in this function [-Wmaybe-uninitialized]
         all += num[i] / i;
         ~~~~^~~~~~~~~~~~~

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