#include<bits/stdc++.h>
#include<string.h>
#include <algorithm>
#include <iterator>
#include <set>
#include <stdlib.h>
#define ll long long
#define fr first
#define sc second
#define pb push_back
#define YES cout<<"YES"<<endl
#define NO cout<<"NO"<<endl
#define endl "\n"
using namespace std;
ll a,b,c,d,e,f,m,i,j,n,h,g,mid,l,r,ka,dp[200005],q[200005],k[200105];
map<ll,ll> mee,see;
map<ll,ll> mii,maa;
vector<ll> vas,ves;
string x,y,z,te,to;
pair<ll,ll> wefe,t[205005];
stack<ll> munkh;
multiset<ll> mul;
ll tree[300005*4];
void build(ll node, ll l, ll r){
if(l==r){
tree[node]=k[l];
}
else{
ll m=(l+r-1)/2;
build(node*2,l,m);
build(node*2+1,m+1,r);
tree[node]=max(tree[node*2],tree[node*2+1]);
}
}
void update(ll node, ll l, ll r, ll m, ll n){
if(l>m){
return;
}
if(r<m){
return;
}
if(l==r){
tree[node]=n;
return;
}
ll mid=(l+r-1)/2;
update(node*2,l,mid,m,n);
update(node*2+1,mid+1,r,m,n);
tree[node]=max(tree[node*2],tree[node*2+1]);
}
ll query(ll node, ll l, ll r,ll m, ll n){
if(r<m || l>n){
return -1;
}
else{
if(l>=m && r<=n){
return tree[node];
}
ll mid=(l+r-1)/2;
return max(query(node*2,l,mid,m,n),query(node*2+1,mid+1,r,m,n));
}
}
int main(){
cin>>a>>b;
cin>>x;
for(i=0 ; i<a ; i++){
if(x[i]=='1'){
k[i]=-1;
}
else{
k[i]=1e6;
}
}
build(1,0,a-1);
for(i=0 ; i<b ; i++){
cin>>y;
if(y[0]=='q'){
cin>>l>>r;
if(i-query(1,0,a-1,l-1,r-2)<0){
cout<<0<<endl;
continue;
}
cout<<i-query(1,0,a-1,l-1,r-2)<<endl;
}
else{
cin>>l;
if(x[l-1]=='0'){
x[l-1]='1';
update(1,0,a-1,l-1,i);
}
}
}
}
