#include <bits/stdc++.h>
#define sz(x) (int) (x).size()
#define all(x) (x).begin(), (x).end()
using namespace std;
typedef pair<int,int> ii;
int n, Q, SZ;
struct query{
int l, r, t, ans;
bool operator< (const query &Q){
return this->r > Q.r;
}
};
struct update{
int l, r, t;
bool operator< (const update &U){
return this->r > U.r;
}
};
namespace fenwick{
int n = 300005;
int tree[300007];
vector<ii> toundo;
void update(int i, int v, bool undo = false){
if(!undo) toundo.push_back(ii(i,v));
for(;i <= n;i += i&(-i)) tree[i] += v;
}
int query(int i){
int ans = 0;
for(;i > 0;i -= i&(-i)) ans += tree[i];
return ans;
}
void undo(){
for(ii B : toundo) update(B.first, -B.second, true);
toundo.clear();
}
};
set<ii> pairs;
vector<int> leafs;
vector<query> queries[600006];
vector<update> updates[600006];
void makeupdate(int l, int r, int t, bool add){
if(add){
pairs.insert(ii(l,r));
updates[leafs[t]].push_back({l,r,-t});
}
else{
pairs.erase(ii(l,r));
updates[leafs[t]].push_back({l,r,t});
}
}
void makequery(int l, int r, int t){
auto it = pairs.upper_bound(ii(l,1e9));
int ans = 0;
if(it != pairs.begin()){
it--;
if(it->first <= l && r <= it->second) ans = t;
}
queries[leafs[t]].push_back({l, r, t, ans});
}
void dfs(int u){
if(u >= 2*SZ) return;
if(u >= SZ) leafs.push_back(u);
dfs(u<<1); dfs(u<<1|1);
}
int arr[300005];
int main(){
ios_base::sync_with_stdio(false); cin.tie(0);
cin >> n >> Q; SZ = Q+1;
string original; cin >> original;
for(int i = 1;i <= n;i++) arr[i] = original[i-1] - '0';
int l = -1;
for(int i = 1;i <= n;i++){
if(arr[i] == 1 && l == -1) l = i;
if(arr[i] == 1 && arr[i+1] == 0){
pairs.insert(ii(l,i));
l = -1;
}
}
for(int i = 1;i <= n;i++) assert(fenwick::tree[i] == 0);
dfs(1);
for(int t = 1;t <= Q;t++){
string s; cin >> s;
if(s[0] == 't'){
int x; cin >> x;
if(arr[x] == 0){ ///turn on
makeupdate(x,x,t,true);
if(arr[x-1] == 1){
auto it = pairs.lower_bound(ii(x,-1));
auto pre = prev(it);
makeupdate(pre->first, it->second, t, true);
makeupdate(pre->first, pre->second, t, false);
makeupdate(it->first, it->second, t, false);
}
if(arr[x+1] == 1){
auto nxt = pairs.upper_bound(ii(x,1e9));
auto it = prev(nxt);
makeupdate(it->first, nxt->second, t, true);
makeupdate(nxt->first, nxt->second, t, false);
makeupdate(it->first, it->second, t, false);
}
arr[x] = 1;
}
else{
auto it = --pairs.upper_bound(ii(x,1e9));
if(it->first != x) makeupdate(it->first, x-1, t, true); // pairs.insert(ii(it->first,x-1));
if(it->second != x) makeupdate(x+1, it->second, t, true);
pairs.erase(it);
makeupdate(it->first, it->second, t, false);
arr[x] = 0;
}
}
else{
int l, r; cin >> l >> r;
makequery(l, r-1, t);
}
}
for(int node = SZ;node < 2*SZ;node++){
sort(all(queries[node]));
sort(all(updates[node]));
}
for(int node = SZ-1;node >= 1;node--){
int LC = node<<1, RC = node<<1|1;
auto it = updates[LC].begin();
for(query &q : queries[RC]){
while(it != updates[LC].end()){
if(it->r < q.r) break;
else{
fenwick::update(it->l, it->t);
it++;
}
}
q.ans += fenwick::query(q.l);
}
fenwick::undo();
merge(all(queries[LC]), all(queries[RC]), back_inserter(queries[node]));
merge(all(updates[LC]), all(updates[RC]), back_inserter(updates[node]));
}
sort(all(queries[1]), [&](query a, query b){ return a.t < b.t; });
for(query q : queries[1]) cout << q.ans << "\n";
}
