N,Q = map(int,input().split()) S = input() taiou = [0] * (N+1) parent = [0] * (N+1) stack = [] for i in range(N): if S[i] == "(": stack.append(i+1) else: x = stack.pop() taiou[x] = i+1 taiou[i+1] = x if stack: p = stack[-1] parent[x] = p parent[i+1] = x else: parent[i+1] = x G = [[] for _ in range(N+1)] for i in range(1,N+1): p = parent[i] G[p].append(i) G[i].append(p) #HL分解 class HL: #u,vを結ぶpathへのクエリはここにでも # f は区間 [l,r)に対するクエリ def f(self,l,r): pass def merge(self,x,y): return x + y def __init__(self,G,root): self.G = G self.root = root self.N = len(G) self.size = [1] * self.N #部分木のサイズ self.p = [0] * self.N #親頂点 self.H = [None] * self.N #Heavy_edgeでつながる子頂点。葉ではNoneが入ってる self._in = [-1] * self.N #最初に探索したときの位置 self.out = [-1] * self.N #部分木をでるタイミング。オイラーとはちょっと違う。 #開区間 [_in[i],out[i]) がiの部分木に対応 self.pathtop = [0] * self.N #iの属するpathの中で最も根に近い頂点。代表にする self.build() self.build_path() def build(self): stack = [(~self.root,-1),(self.root,-1)] G = self.G size = self.size H = self.H while stack: now,parent = stack.pop() if now < 0: now = ~now _max = 0 for v in G[now]: if v == parent:continue size[now] += size[v] if size[v] > _max: _max = size[v] H[now] = v else: for v in G[now]: if v == parent:continue self.p[v] = now stack.append((~v,now)) stack.append((v,now)) def build_path(self): stack = [(~self.root,-1,self.root),(self.root,-1,self.root)] count = 0 G = self.G H = self.H while stack: now,parent,top = stack.pop() if now >= 0: self._in[now] = count count += 1 self.pathtop[now] = top h = H[now] if h is None:continue for v in G[now]: if v == parent or v == h:continue stack.append((~v,now,v)) stack.append((v,now,v)) stack.append((~h,now,top)) stack.append((h,now,top)) else: now = ~now self.out[now] = count def lca(self,a,b): #最近共通先祖 pathtop = self.pathtop _in = self._in pa = pathtop[a] pb = pathtop[b] while pa != pb: if _in[pa] > _in[pb]: a = self.p[pa] pa = pathtop[a] else: b = self.p[pb] pb = pathtop[b] return a if _in[a] < _in[b] else b def subtree_query(self,a,f = None): #if f is None:f = self.f return f(self._in[a],self.out[a]) def subtree_array(self,a): return (self._in[a],self.out[a]) #下のpath_arrayとほぼ同じ。タプルを一つだけ返す #f = lambda l,r:seg.fold(l,r) とか #f = lambda l,r:seg.oparete_range(l,r,x) とか #代入して使う def path_query(self,a,b,f = None,merge = None): #if f is None:f = self.f #if merge is None:merge = self.merge pathtop = self.pathtop p = self.p _in = self._in pa = pathtop[a] pb = pathtop[b] ans = 0 while pa != pb: if _in[pa] > _in[pb]: ans = merge(ans,f(_in[pa],_in[a]+1)) a = p[pa] pa = pathtop[a] else: ans = merge(ans,f(_in[pb],_in[b]+1)) b = p[pb] pb = pathtop[b] if _in[a] > _in[b]: a,b = b,a ans = merge(ans,f(_in[a],_in[b]+1)) return ans def path_array(self,a,b): # a,b を結ぶpath、を分割した配列を返す。こっちのほうが便利かも #半開区間 [l,r) の集まりを返す #現状順番は適当 #こっちのほうが早かった pathtop = self.pathtop p = self.p _in = self._in ans = [] pa = pathtop[a] pb = pathtop[b] while pa != pb: if _in[pa] > _in[pb]: ans.append((_in[pa],_in[a]+1)) a = p[pa] pa = pathtop[a] else: ans.append((_in[pb],_in[b]+1)) b = p[pb] pb = pathtop[b] if _in[a] > _in[b]: a,b = b,a ans.append((_in[a],_in[b]+1)) return ans hl = HL(G,0) for _ in range(Q): x,y = map(int,input().split()) ans = hl.lca(x,y) if ans == 0: print(-1) else: print(ans,taiou[ans])