foo.cc: In function 'int main()':
foo.cc:9:8: warning: unused variable 'a' [-Wunused-variable]
    9 |  int n,a,b,nn=0;
      |        ^
foo.cc:9:10: warning: unused variable 'b' [-Wunused-variable]
    9 |  int n,a,b,nn=0;
      |          ^
foo.cc: In function 'int wsq(int)':
foo.cc:29:12: warning: comparison of integer expressions of different signedness: 'int' and 'size_t' {aka 'long unsigned int'} [-Wsign-compare]
   29 |   for(i=0;i<strlen(www);i++)
      |           ~^~~~~~~~~~~~

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