foo.cc: In function 'int main()':
foo.cc:59:7: warning: unused variable 'flag' [-Wunused-variable]
   59 |  bool flag=false;
      |       ^~~~
foo.cc:65:6: warning: unused variable 's' [-Wunused-variable]
   65 |  int s=1;
      |      ^
foo.cc: In function 'int dsom(int, int)':
foo.cc:38:1: warning: control reaches end of non-void function [-Wreturn-type]
   38 | }
      | ^

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