/in/foo.cc: In function 'int main()':
/in/foo.cc:52:11: warning: 'r' may be used uninitialized in this function [-Wmaybe-uninitialized]
   qwq[i]=r-l;
          ~^~
/in/foo.cc:52:11: warning: 'l' may be used uninitialized in this function [-Wmaybe-uninitialized]