/in/foo.cc: In function 'int main()':
/in/foo.cc:16:4: warning: unused variable 'k' [-Wunused-variable]
 ll k, m, x, y, l, r, ans = 0;
    ^
/in/foo.cc:16:7: warning: unused variable 'm' [-Wunused-variable]
 ll k, m, x, y, l, r, ans = 0;
       ^
/in/foo.cc:16:16: warning: unused variable 'l' [-Wunused-variable]
 ll k, m, x, y, l, r, ans = 0;
                ^
/in/foo.cc:16:19: warning: unused variable 'r' [-Wunused-variable]
 ll k, m, x, y, l, r, ans = 0;
                   ^