foo.cc: In function 'int main()':
foo.cc:30:10: warning: unused variable 'n1' [-Wunused-variable]
   30 |  int num,n1,n2,L,k,n,i;
      |          ^~
foo.cc:35:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   35 |   scanf("%d",&x);
      |   ~~~~~^~~~~~~~~
foo.cc:55:8: warning: 'num' may be used uninitialized in this function [-Wmaybe-uninitialized]
   55 |  cout<<num;
      |        ^~~

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