#include<bits/stdc++.h>

using namespace std;

#define ll long long
#define ull unsigned ll
#define i128 __int128
#define db double
#define ld long db

#define M 6000005
#define N 300005
#define mod 1000000009
#define mod2 1222827239
#define base 51787
#define base2 38833
#define inf 1e9+7
#define dinf 1e15
#define linf 7e18

#define LOCAL

namespace qwq{
    namespace IO{
    	
        #ifndef LOCAL
            #define SIZE (1<<20)
            char in[SIZE],out[SIZE],*p1=in,*p2=in,*p3=out;
            #define getchar() (p1==p2&&(p2=(p1=in)+fread(in,1,SIZE,stdin),p1==p2)?EOF:*p1++)
            #define flush() (fwrite(p3=out,1,SIZE,stdout))
            #define putchar(ch) (p3==out+SIZE&&flush(),*p3++=(ch))
            class Flush{public:~Flush(){flush();}}_;
        #endif
        
        template<typename type>
        inline void read(type &x){
            x=0;bool flag(0);char ch=getchar();
            while(!isdigit(ch)) flag^=ch=='-',ch=getchar();
            while(isdigit(ch)) x=(x<<1)+(x<<3)+(ch^48),ch=getchar();
            flag?x=-x:0;
        }
        
        template<typename type>
        inline void write(type x,bool flag=1){
            x<0?x=-x,putchar('-'):0;static short Stack[50],top(0);
            do Stack[++top]=x%10,x/=10;while(x);
            while(top) putchar(Stack[top--]|48);
            flag?putchar('\n'):putchar(' ');
        }
        
        #ifndef LOCAL
            #undef SIZE
            #undef getchar
            #undef putchar
            #undef flush
        #endif
    }
} using namespace qwq::IO;

int n,q;
char c[N];
bool s[N];

int rt[N],tot;

struct segment_tree{
	bool sum[M];
	int ls[M],rs[M];
	
	void push_up(int p){
		sum[p]=sum[ls[p]]&sum[rs[p]];
	}
	
	int build(int l,int r){
		int p=++tot;
		if(l==r){
			sum[p]=s[l];
			return p;
		}
		int mid=(l+r)>>1;
		ls[p]=build(l,mid);
		rs[p]=build(mid+1,r);
		push_up(p);
		return p;
	}
	
	int clone(int p){
		int x=++tot;
		sum[x]=sum[p];
		ls[x]=ls[p];
		rs[x]=rs[p];
		return x;
	}
	
	int update(int p,int i,int L,int R){
		p=clone(p);
		if(L==R){
			sum[p]^=1;
			return p;
		}
		int mid=(L+R)>>1;
		if(i<=mid) ls[p]=update(ls[p],i,L,mid);
		else rs[p]=update(rs[p],i,mid+1,R);
		push_up(p);
		return p;
	}
	
	bool query(int p,int l,int r,int L,int R){
		if(l<=L&&R<=r) return sum[p];
		int mid=(L+R)>>1;
		if(r<=mid) return query(ls[p],l,r,L,mid);
		if(l>mid) return query(rs[p],l,r,mid+1,R);
		return query(ls[p],l,r,L,mid)&query(rs[p],l,r,mid+1,R);
	}
}t;

int main(){
	read(n); read(q);
	scanf("%s",c+1);
	for(int i=1;i<=n;++i) s[i]=(c[i]=='1');
	rt[0]=t.build(1,n);
	char op[7];
	for(int p=1;p<=q;++p){
		scanf("%s",op);
		if(op[0]=='t'){
			int i;
			read(i);
			rt[p]=t.update(rt[p-1],i,1,n);
		} else {
			int l,r;
			read(l); read(r);
			int L=0,R=p-1,res=p;
			while(L<=R){
				int mid=(L+R)>>1;
				if(t.query(rt[mid],l,r,1,n)) res=mid,R=mid-1;
				else L=mid+1;
			}
			printf("%d\n",p-res);
			rt[p]=rt[p-1];
		}
	}
	return 0;
} // sub3