#include <bits/stdc++.h>
using namespace std;
#define pii pair<int,int>
#define fs first
#define sc second
const int mxn = 3e5+10;
int N,Q;
int arr[mxn];
pii tree[mxn];
pii req[mxn];
namespace TREE{
int par[mxn][20];
int dep[mxn];
vector<int> st;
void dfs(int now){
for(int i = 1;i<20;i++){
par[now][i] = par[par[now][i-1]][i-1];
}
if(tree[now].fs){
par[tree[now].fs][0] = now;
dep[tree[now].fs] = dep[now]+1;
dfs(tree[now].fs);
}
if(tree[now].sc){
par[tree[now].sc][0] = now;
dep[tree[now].sc] = dep[now]+1;
dfs(tree[now].sc);
}
return;
}
void BUILD(){
for(int i = 1;i<=N;i++){
while(!st.empty()&&arr[st.back()]<=arr[i]){
tree[i].fs = st.back();
st.pop_back();
}
if(!st.empty()){
tree[st.back()].sc = i;
}
st.push_back(i);
}
par[st[0]][0] = st[0];
dfs(st[0]);
}
int LCA(int a,int b){
if(dep[a]<dep[b])swap(a,b);
int d = dep[a]-dep[b];
for(int i = 19;i>=0;i--){
if(d&(1<<i))a = par[a][i];
}
for(int i = 19;i>=0;i--){
if(par[a][i] != par[b][i])a = par[a][i],b = par[b][i];
}
return a== b?a:par[a][0];
}
}
int main(){
ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
cin>>N>>Q;
if(N>mxn||Q>mxn)return 0;
string s;
cin>>s;
s = "#"+s;
fill(arr,arr+mxn,mxn);
for(int i = 1;i<=N;i++){
if(s[i] == '1')arr[i] = 0;
}
for(int i = 1;i<=Q;i++){
string t;
cin>>t;
if(t[0] == 'q'){
cin>>req[i].fs>>req[i].sc;
}
else{
req[i].fs = 0;
cin>>req[i].sc;
arr[req[i].sc] = i;
}
}
TREE::BUILD();
for(int i = 1;i<=Q;i++){
if(req[i].fs){
int p = TREE::LCA(req[i].fs,req[i].sc-1);
cout<<max(0,i-arr[p])<<'\n';
}
}
return 0;
}
