foo.cc: In function 'void Pushdown(int)':
foo.cc:38:13: warning: operation on 'T[((k << 1) | 1)].Tree::lcb' may be undefined [-Wsequence-point]
   T[rs].lcb = T[rs].lcb = T[rs].maxb = T[rs].siz;
   ~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
foo.cc:45:13: warning: operation on 'T[((k << 1) | 1)].Tree::lca' may be undefined [-Wsequence-point]
   T[rs].lca = T[rs].lca = T[rs].maxa = T[rs].sum = T[rs].siz;
   ~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
foo.cc: In function 'void Build(int, int, int)':
foo.cc:98:14: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  int mid = l + r >> 1;
            ~~^~~
foo.cc: In function 'void Update(int, int, int, int)':
foo.cc:125:19: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  int mid = T[k].l + T[k].r >> 1;
            ~~~~~~~^~~~~~~~
foo.cc: In function 'void Change(int, int, int)':
foo.cc:158:19: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  int mid = T[k].l + T[k].r >> 1;
            ~~~~~~~^~~~~~~~
foo.cc: In function 'int Query1(int, int, int)':
foo.cc:168:19: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  int mid = T[k].l + T[k].r >> 1, res = 0;
            ~~~~~~~^~~~~~~~
foo.cc: In function 'int Query2(int, int, int)':
foo.cc:178:19: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  int mid = T[k].l + T[k].r >> 1, res = 0;
            ~~~~~~~^~~~~~~~
foo.cc: In function 'int main()':
foo.cc:187:24: warning: unused variable 'mm' [-Wunused-variable]
  read(n); read(m); int mm = m;
                        ^~

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