foo.cc:10:18: warning: suggest parentheses around '+' inside '<<' [-Wparentheses]
   10 | } tree[MAXN << 2 + 1];
      |                ~~^~~
foo.cc: In function 'int main()':
foo.cc:128:22: error: too few arguments to function 'long long int query(int, int, int)'
  128 |    cout << query(1, x) + query(y, n) << endl;
      |                      ^
foo.cc:52:11: note: declared here
   52 | long long query(int l, int r, int k){
      |           ^~~~~
foo.cc:128:36: error: too few arguments to function 'long long int query(int, int, int)'
  128 |    cout << query(1, x) + query(y, n) << endl;
      |                                    ^
foo.cc:52:11: note: declared here
   52 | long long query(int l, int r, int k){
      |           ^~~~~

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