/in/foo.cc: In function 'int main()':
/in/foo.cc:16:5: warning: unused variable 'k' [-Wunused-variable]
  ll k, m, x, y, l, r, ans = 0;
     ^
/in/foo.cc:16:8: warning: unused variable 'm' [-Wunused-variable]
  ll k, m, x, y, l, r, ans = 0;
        ^
/in/foo.cc:16:17: warning: unused variable 'l' [-Wunused-variable]
  ll k, m, x, y, l, r, ans = 0;
                 ^
/in/foo.cc:16:20: warning: unused variable 'r' [-Wunused-variable]
  ll k, m, x, y, l, r, ans = 0;
                    ^