#include <bits/stdc++.h>
using namespace std;
#define endl "\n"
#define int long long
using ull=unsigned long long;
using ll=long long;
using pii=pair<int,int>;
const int dx[4] = {1,0,-1,0}, dy[4] = {0,1,0,-1};
const int mod=1e9+7;
#define OVL(x,s) for(auto y:x) cout<<y<<s; cout<<"\n";
template <typename T> istream& operator>>(istream& is, vector<T> &a) {
copy_n(istream_iterator<T>(is), a.size(), a.begin()); return is;}
#ifdef IOI
template<typename A, typename B> ostream& operator<<(ostream &os, const pair<A, B> &p) { return os << '(' << p.first << ", " << p.second << ')'; }
template<typename T_container, typename T = typename enable_if<!is_same<T_container, string>::value, typename T_container::value_type>::type> ostream& operator<<(ostream &os, const T_container &v) { os << '{'; string sep; for (const T &x : v) os << sep << x, sep = ", "; return os << '}'; }
void dbg_out() { cout << endl; }
template<typename Head, typename... Tail> void dbg_out(Head H, Tail... T) { cout << ' ' << H; dbg_out(T...); }
#define dbg(...) cout << "(" << #__VA_ARGS__ << "):", dbg_out(__VA_ARGS__);
#else
#define dbg(...) 1337;
#endif
#define pb push_back
#define F first
#define S second
#define all(v) v.begin(),v.end()
struct Node{
int mx;
int sum;
Node* left,*right;
Node() : mx(0),sum(0),left(nullptr),right(nullptr) {}
};
Node* root=new Node();
void update(Node* node,int l,int r,int ql,int x){
if(l==r){
node->mx=x;
node->sum=x;
return;
}
int mid=(l+r)/2;
if(ql<=mid){
if(node->left==nullptr) node->left=new Node();
update(node->left,l,mid,ql,x);
}else{
if(node->right==nullptr) node->right=new Node();
update(node->right,mid+1,r,ql,x);
}
node->sum=(node->left?node->left->sum:0LL)+(node->right?node->right->sum:0LL);
node->mx=max((node->left?node->left->mx:0LL),(node->right?node->right->mx:0LL));
}
int querymx(Node* node,int l,int r,int ql,int qr){
if(!node) return 0;
if(ql<=l&&r<=qr) return node->mx;
int mid=(l+r)/2;
int ans=0;
if(ql<=mid&&node->left) ans=max(ans,querymx(node->left,l,mid,ql,qr));
if(qr>mid&&node->right) ans=max(ans,querymx(node->right,mid+1,r,ql,qr));
return ans;
}
signed main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
int n;
cin>>n;
int q;
cin>>q;
string s;
cin>>s;
Node* root = new Node();
for(int i = 0;i<n;i++){
if(s[i]=='1'){
update(root,0,n-1,i,0);
}else{
update(root,0,n-1,i,1e18);
}
}
for(int j =1;j<=q;j++){
string a;
cin>>a;
if(a[0]=='t'){
int i;
cin>>i;
i--;
int x = s[i]-'0';
x^=1;
if(x==1){
update(root,0,n-1,i,j);
}
}else{
int a,b;
cin>>a>>b;
a--,b--;b--;
int x = querymx(root,0,n-1,a,b);
int ans = j-x;
ans = max(ans,0LL);
cout<<ans<<endl;
}
}
}
