#include<cstdio>

#include<cstring>

#include<iostream>

#define MAXN 100500

using namespace std;

char s[10];

int N,M;

struct SPT{

	int pmx[MAXN],pmn[MAXN],smx[MAXN],smn[MAXN],sum[MAXN],key[MAXN];

	int ch[MAXN][2],siz[MAXN],fa[MAXN],cg[MAXN],lazy[MAXN],rt;

	void Invert(int x){

		sum[x]*=-1; key[x]*=-1;

		pmx[x]*=-1; pmn[x]*=-1; swap(pmx[x],pmn[x]);

		smx[x]*=-1; smn[x]*=-1; swap(smx[x],smn[x]);

	}

	void Swap(int x){

		swap(pmx[x],smx[x]);

		swap(pmn[x],smn[x]);

		swap(ch[x][0],ch[x][1]);

	}

	void Replace(int x,int c){

		key[x]=c; sum[x]=c*siz[x];

		pmx[x]=max(sum[x],0); pmn[x]=min(sum[x],0);

		smx[x]=max(sum[x],0); smn[x]=min(sum[x],0);

	}

	void Pushup(int x){

		siz[x]=siz[ch[x][0]]+1+siz[ch[x][1]];

		sum[x]=sum[ch[x][0]]+key[x]+sum[ch[x][1]];

		pmx[x]=max(pmx[ch[x][0]],sum[ch[x][0]]+key[x]+pmx[ch[x][1]]);

		pmn[x]=min(pmn[ch[x][0]],sum[ch[x][0]]+key[x]+pmn[ch[x][1]]);

		smx[x]=max(smx[ch[x][1]],sum[ch[x][1]]+key[x]+smx[ch[x][0]]);

		smn[x]=min(smn[ch[x][1]],sum[ch[x][1]]+key[x]+smn[ch[x][0]]);

	}

	void Pushdown(int x){

		if(cg[x]!=0){

			Replace(ch[x][0],cg[x]); cg[ch[x][0]]=cg[x]; lazy[ch[x][0]]=0;

			Replace(ch[x][1],cg[x]); cg[ch[x][1]]=cg[x]; lazy[ch[x][1]]=0;

			cg[x]=0;

		}

		if(lazy[x]&1){

			Invert(ch[x][0]);

			if(!cg[ch[x][0]]) lazy[ch[x][0]]^=1; else cg[ch[x][0]]*=-1;

			Invert(ch[x][1]);

			if(!cg[ch[x][1]]) lazy[ch[x][1]]^=1; else cg[ch[x][1]]*=-1;

			lazy[x]^=1;

		}

		if(lazy[x]&2){

			Swap(ch[x][0]);

			if(!cg[ch[x][0]]) lazy[ch[x][0]]^=2;

			Swap(ch[x][1]);

			if(!cg[ch[x][1]]) lazy[ch[x][1]]^=2;

			lazy[x]^=2;

		}

	}

	void Rotate(int x,int &k){

		static int y,z,l,r;

		y=fa[x]; z=fa[y];

		l=ch[y][0]!=x; r=l^1;

		if(!z) k=x;

		else ch[z][ch[z][0]!=y]=x;

		fa[ch[x][r]]=y; fa[y]=x; fa[x]=z;

		ch[y][l]=ch[x][r]; ch[x][r]=y;

		Pushup(y);

	}

	void Splay(int x,int &k){

		static int y,z;

		while(x!=k){

			y=fa[x]; z=fa[y];

			if(y!=k) (ch[z][0]!=y)^(ch[y][0]!=x)?

				Rotate(x,k):Rotate(y,k);

			Rotate(x,k);

		}

		Pushup(x);

	}

	int find(int x,int num){

		Pushdown(x);

		if(num<=siz[ch[x][0]]) return find(ch[x][0],num);

		else if(num==siz[ch[x][0]]+1) return x;

		else return find(ch[x][1],num-siz[ch[x][0]]-1);

	}

	int Split(int l,int r){

		static int dl,dr;

		dl=find(rt,l); dr=find(rt,r+2);

		Splay(dl,rt); Splay(dr,ch[dl][1]);

		return ch[dr][0];

	}

	void Modify(int l,int r,int type){

		static int p;

		p=Split(l,r);

		if(type==3){

			Replace(p,(s[0]=='('?1:-1));

			cg[p]=(s[0]=='('?1:-1); lazy[p]=0;

		}

		else{

			if(type==1) Invert(p);

			else Swap(p);

			if(!cg[p]) lazy[p]^=type;

			else if(type==1) cg[p]*=-1;

		}

		Pushup(fa[p]); Pushup(fa[fa[p]]);

	}

	void Build(int &x,int dad,int l,int r){

		static char c;

		if(l>r) return;

		x=(l+r)>>1; fa[x]=dad;

		Build(ch[x][0],x,l,x-1);

		scanf(" %c",&c); key[x]=(c=='('?1:-1);

		Build(ch[x][1],x,x+1,r);

		Pushup(x);

	}

	void BorderBuild(){

		rt=N+1;

		key[N+1]=0; key[N+2]=0;

		ch[N+1][1]=N+2; fa[N+2]=N+1;

		Build(ch[N+2][0],N+2,1,N);

		Pushup(N+2); Pushup(N+1);

	}

	int Query(int l,int r){

		static int p,ANS,nl,nr;

		p=Split(l,r);

		nl=-pmn[p]; nr=smx[p];

		ANS=(nl+1)/2+(nr+1)/2;

		return ANS;

	}

}DT;

int main(){

	freopen("/home/noilinux/Documents/模块学习/2329.in","r",stdin);

	freopen("/home/noilinux/Documents/模块学习/2329.out","w",stdout);

	scanf("%d%d",&N,&M);

	DT.BorderBuild();

	for(int i=1,l,r;i<=M;i++){

		scanf("%s",s); scanf("%d%d",&l,&r);

		if(s[0]=='Q') printf("%d\n",DT.Query(l,r));

		if(s[0]=='I') DT.Modify(l,r,1);

		if(s[0]=='S') DT.Modify(l,r,2);

		if(s[0]=='R') scanf("%s",s),DT.Modify(l,r,3);

	}

	return 0;

}