func main() var n: int :: cui@inputInt() var s: []char :: cui@input() var t: []char :: cui@input() var set: Set :: #Set for i(0, n - 1) if(s[i] <> t[i]) do set.add(i) end if end for var q: int :: cui@inputInt() for(1, q) var c: char :: cui@inputChar() var x: int :: cui@inputInt() - 1 var y: int :: cui@inputInt() if(c = 'S') do s[x] :: '0'.offset(y) else do t[x] :: '0'.offset(y) end if if(s[x] = t[x]) do set.del(x) else do set.add(x) end if var begin: Node :: set.begin() if(begin =& null) do cui@print("=") else var i: int :: begin.key if(s[i] < t[i]) do cui@print("<") elif(s[i] > t[i]) do cui@print(">") end if end if do cui@print("\n") end for class Node() +var height: int +var key: int +var prev: Node +var next: Node +var lst: Node +var rst: Node +*func toStr(): []char ret me.key.toStr() end func +func init(key: int, prev: Node, next: Node): Node do me.height :: 1 do me.key :: key do me.prev :: prev do me.next :: next ret me end func end class ; AVL Tree class Set() var root: Node var change: bool var lMax: int var num: int +func size(): int ret me.num end func +func begin(): Node var t: Node :: me.root if(t =& null) ret null end if while(true) if(t.lst =& null) ret t end if do t :: t.lst end while end func func height(t: Node): int ret t =& null ?(0, t.height) end func func bias(t: Node): int ret me.height(t.lst) - me.height(t.rst) end func func modHeight(t: Node) do t.height :: 1 + lib@max(me.height(t.lst), me.height(t.rst)) end func func rotateL(v: Node): Node var u: Node :: v.rst var t: Node :: u.lst do u.lst :: v do v.rst :: t ret u end func func rotateR(u: Node): Node var v: Node :: u.lst var t: Node :: v.rst do v.rst :: u do u.lst :: t ret v end func func rotateLR(t: Node): Node do t.lst :: me.rotateL(t.lst) ret me.rotateR(t) end func func rotateRL(t: Node): Node do t.rst :: me.rotateR(t.rst) ret me.rotateL(t) end func func balanceL(t: Node): Node if(!me.change) ret t end if var h: int :: me.height(t) if(me.bias(t) = 2) if(me.bias(t.lst) >= 0) do t :: me.rotateR(t) else do t :: me.rotateLR(t) end if else do me.modHeight(t) end if do me.change :: h <> me.height(t) ret t end func +func balanceR(t: Node): Node if(!me.change) ret t end if var h: int :: me.height(t) if(me.bias(t) = -2) if(me.bias(t.rst) <= 0) do t :: me.rotateL(t) else do t :: me.rotateRL(t) end if else do me.modHeight(t) end if do me.change :: h <> me.height(t) ret t end func +func add(key: int) do me.root :: me.addSub(me.root, null, key) end func func addSub(t: Node, parent: Node, key: int): Node if(t =& null) var a: Node do me.change :: true if(parent =& null) do a :: (#Node).init(key, null, null) elif(key < parent.key) do a :: (#Node).init(key, parent.prev, parent) if(parent.prev <>& null) do parent.prev.next :: a end if do parent.prev :: a elif(key > parent.key) do a :: (#Node).init(key, parent, parent.next) if(parent.next <>& null) do parent.next.prev :: a end if do parent.next :: a end if do me.num :+ 1 ret a elif(key < t.key) do t.lst :: me.addSub(t.lst, t, key) ret me.balanceL(t) elif(key > t.key) do t.rst :: me.addSub(t.rst, t, key) ret me.balanceR(t) else do me.change :: false ret t end if end func +func del(key: int) do me.root :: me.delSub(me.root, key) end func func delSub(t: Node, key: int): Node if(t =& null) do me.change :: false ret null elif(key < t.key) do t.lst :: me.delSub(t.lst, key) ret me.balanceR(t) elif(key > t.key) do t.rst :: me.delSub(t.rst, key) ret me.balanceL(t) else do me.num :- 1 if(t.next <>& null) do t.next.prev :: t.prev end if if(t.prev <>& null) do t.prev.next :: t.next end if if(t.lst =& null) do me.change :: true ret t.rst else do t.lst :: me.delMax(t.lst) do t.key :: me.lMax ret me.balanceR(t) end if end if end func func delMax(t: Node): Node if(t.rst <>& null) do t.rst :: me.delMax(t.rst) ret me.balanceL(t) else do me.change :: true do me.lMax :: t.key ret t.lst end if end func +func find(key: int): Node var t: Node :: me.root while loop(t <>& null) if(key < t.key) do t :: t.lst elif(key > t.key) do t :: t.rst else break loop end if end while ret t end func +func exist(key: int): bool ret me.find(key) <>& null end func +func lower_bound(key: int): Node var t: Node :: me.root if(t =& null) ret null end if while(true) if(key < t.key) if(t.lst =& null) ret t end if if(key > t.lst.key & t.lst.rst =& null) ret t end if do t :: t.lst elif(key > t.key) if(t.rst =& null) ret null end if do t :: t.rst else ret t end if end while end func end class end func