foo.cc: In function 'int main()':
foo.cc:24:10: warning: unused variable 'n1' [-Wunused-variable]
  int num,n1,n2,L,k,n;
          ^~
foo.cc:27:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d",&x);
   ~~~~~^~~~~~~~~
foo.cc:25:15: warning: 'n' is used uninitialized in this function [-Wuninitialized]
  for(int i=0;i<n;i++){
              ~^~
foo.cc:31:6: warning: 'k' is used uninitialized in this function [-Wuninitialized]
  L=n2-k+1;
    ~~^~
foo.cc:44:6: warning: 'num' may be used uninitialized in this function [-Wmaybe-uninitialized]
  cout<<num;
  ~~~~^~~~~

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