#include <cstdio>

#include <cstring>

#include <cmath>

#include <string>

#include <iostream>

#include <algorithm>

#include <queue>

#include <set>

#include <map>

using namespace std;

typedef long long ll;

#define rep(i, n) for(int i=0; i<(n); ++i)

#define for1(i,a,n) for(int i=(a);i<=(n);++i)

#define for2(i,a,n) for(int i=(a);i<(n);++i)

#define for3(i,a,n) for(int i=(a);i>=(n);--i)

#define for4(i,a,n) for(int i=(a);i>(n);--i)

#define CC(i,a) memset(i,a,sizeof(i))

#define read(a) a=getint()

#define print(a) printf("%d", a)

#define dbg(x) cout << (#x) << " = " << (x) << endl

#define error(x) (!(x)?puts("error"):0)

#define rdm(x, i) for(int i=ihead[x]; i; i=e[i].next)

inline const int getint() { int r=0, k=1; char c=getchar(); for(; c<'0'||c>'9'; c=getchar()) if(c=='-') k=-1; for(; c>='0'&&c<='9'; c=getchar()) r=r*10+c-'0'; return k*r; }

const int oo=~0u>>1, N=1e5+10;

struct node *null;

struct node {

	node *f, *c[2];

	int s, k, lmin, lmax, rmin, rmax, sum, fix;

	bool tag, rev;

	node(int _k=0) { s=1; lmin=lmax=rmin=rmax=k=sum=_k; f=c[0]=c[1]=null; tag=rev=0; fix=0; }

	void setc(node *x, bool d) { c[d]=x; x->f=this; }

	bool d() { return f->c[1]==this; }

	void pushup() {

		s=c[0]->s+c[1]->s+1;

		sum=c[0]->sum+c[1]->sum+k;

		lmin=c[0]->lmin;

		lmax=c[0]->lmax;

		rmin=c[1]->rmin;

		rmax=c[1]->rmax;

		int mnl=min(0, c[1]->lmin), mnr=min(0, c[0]->rmin);

		int mxl=max(0, c[1]->lmax), mxr=max(0, c[0]->rmax);

		lmin=min(lmin, c[0]->sum+k+mnl);

		lmax=max(lmax, c[0]->sum+k+mxl);

		rmin=min(rmin, c[1]->sum+k+mnr);

		rmax=max(rmax, c[1]->sum+k+mxr);

	}

	void upd1() {

		if(this==null) return;

		if(fix) fix=-fix;

		tag=!tag; int t;

		t=lmin; lmin=-lmax; lmax=-t;

		t=rmin; rmin=-rmax; rmax=-t;

		k=-k;

		sum=-sum;

	}

	void upd2() {

		if(this==null) return;

		rev=!rev;

		swap(c[0], c[1]);

		swap(lmin, rmin);

		swap(lmax, rmax);

	}

	void upd3(int _k) {

		if(this==null) return;

		fix=_k;

		k=_k;

		sum=s*k;

		lmin=rmin=k<0?sum:k;

		lmax=rmax=k<0?k:sum;

	}

	void pushdown() {

		if(tag) {

			c[0]->upd1();

			c[1]->upd1();

			tag=0;

		}

		if(rev) {

			c[0]->upd2();

			c[1]->upd2();

			rev=0;

		}

		if(fix) {

			c[0]->upd3(fix);

			c[1]->upd3(fix);

			fix=0;

		}

	}

}*root;

void PN(node *x) {

	printf("key:%c \t lmin:%d \t lmax:%d \t rmin:%d \t rmax:%d \t sum:%d \t \n", x->k==1?'(':(x->k==-1?')':'N'), x->lmin, x->lmax, x->rmin, x->rmax, x->sum);

}

void Pr(node *x) {

	if(x==null) return;

	x->pushdown();

	Pr(x->c[0]);

	if(x->k) printf("%c", x->k==1?'(':')');

	Pr(x->c[1]);

}

void P(node *x=root) {

	Pr(x); puts("");

}

void rot(node *x) {

	node *f=x->f;

	f->pushdown(); x->pushdown(); bool d=x->d();

	f->f->setc(x, f->d());

	f->setc(x->c[!d], d);

	x->setc(f, !d);

	f->pushup();

	if(f==root) root=x;

}

void splay(node *x, node *f=null) {

	x->pushdown();

	while(x->f!=f)

		if(x->f->f==f) rot(x);

		else x->d()==x->f->d()?(rot(x->f), rot(x)):(rot(x), rot(x));

	x->pushup();

}

node *sel(node *x, int k) {

	if(x==null) return x;

	x->pushdown();

	int s=x->c[0]->s;

	if(s==k) return x;

	if(s<k) return sel(x->c[1], k-s-1);

	return sel(x->c[0], k);

}

node *getrange(int l, int r) {

	splay(sel(root, l-1));

	splay(sel(root, r+1), root);

	return root->c[1]->c[0];

}

void fix1() {

	int l=getint(), r=getint();

	node *x=getrange(l, r);

	x->pushdown();

	x->upd1();

}

void fix2() {

	int l=getint(), r=getint();

	node *x=getrange(l, r);

	x->pushdown();

	x->upd2();

}

void fix3() {

	int l=getint(), r=getint();

	node *x=getrange(l, r);

	char c=getchar(); while(c!=')'&&c!='(') c=getchar();

	int fix=c==')'?-1:1;

	x->pushdown();

	x->upd3(fix);

}

void ask() {

	int l=getint(), r=getint();

	node *x=getrange(l, r);

	l=(-x->lmin+1)>>1;

	r=(x->rmax+1)>>1;

	printf("%d\n", l+r);

}

char s[N];

int n, m, q;

void build(int l, int r, node *&x) {

	if(l>r) return;

	int mid=(l+r)>>1;

	x=new node(s[mid]==')'?-1:1);

	if(l==r) return;

	build(l, mid-1, x->c[0]);

	build(mid+1, r, x->c[1]);

	if(l<=mid-1) x->c[0]->f=x;

	if(mid+1<=r) x->c[1]->f=x;

	x->pushup();

}

void in(node *x) {

	x->lmax=x->rmax=-oo;

	x->lmin=x->rmin=oo;

	x->sum=0;

	x->k=0;

}

void init() {

	null=new node(); null->s=0; in(null);

	null->f=null->c[0]=null->c[1]=null;

	root=new node(); in(root);

	root->setc(new node(), 1); in(root->c[1]);

	node *x;

	read(n); read(m);

	scanf("%s", s+1);

	build(1, n, x);

	root->c[1]->setc(x, 0);

	root->c[1]->pushup();

	root->pushup();

}

char o[10];

int main() {

	init();

	while(m--) {

		scanf("%s", o);

		if(o[0]=='Q') ask();

		else if(o[0]=='I') fix1();

		else if(o[0]=='S') fix2();

		else fix3();

		//P();

	}

	return 0;

}

Splay