/in/foo.cc: In function 'int main()':
/in/foo.cc:16:7: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
    m=l+r>>1;
      ~^~
/in/foo.cc: In function 'bool check(int)':
/in/foo.cc:43:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^
/in/foo.cc: In function 'int main()':
/in/foo.cc:21:16: warning: 'm' may be used uninitialized in this function [-Wmaybe-uninitialized]
  printf("%d",m);
                ^