/in/foo.cc: In function 'int main()':
/in/foo.cc:33:5: warning: unused variable 'x' [-Wunused-variable]
  ll x,len,l,r;
     ^
/in/foo.cc:33:7: warning: unused variable 'len' [-Wunused-variable]
  ll x,len,l,r;
       ^~~