foo.c: In function 'main':
foo.c:4:17: warning: unused variable 'x1' [-Wunused-variable]
   int n,num=0,x,x1;
                 ^~
foo.c:5:3: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d",&n);
   ^~~~~~~~~~~~~~
foo.c:9:8: warning: 'x' may be used uninitialized in this function [-Wmaybe-uninitialized]
   while(x1<x)
        ^

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