/in/foo.cc: In function 'void build(long long int, long long int, long long int)':
/in/foo.cc:31:17: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   31 |     int mid = l + r >> 1;
      |               ~~^~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:86:15: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17' [-Wc++17-extensions]
   86 |     for (auto [x, y] : lsh) {
      |               ^