#include <bits/stdc++.h>
#define debug(x) cerr << #x << " " << x << "\n"
#define debugs(x) cerr << #x << " " << x << " "
#pragma GCC optimize ("Ofast")
#pragma GCC target ("avx2")
using namespace std;
typedef long long ll;
typedef pair <ll, ll> pii;
const ll NMAX = 300001;
const int INF = 1e9;
const ll nrbits = 20;
const ll MOD = 998244353;
int a[NMAX];
string s[NMAX];
int qa[NMAX];
int qb[NMAX];
int aint[NMAX * 4];
void update(int node, int st, int dr, int a, int b){
if(st == dr){
aint[node] = b;
return;
}
int mid = (st + dr) / 2;
if(a <= mid)
update(node * 2, st, mid, a, b);
else
update(node * 2 + 1, mid + 1, dr, a, b);
aint[node] = max(aint[node * 2], aint[node * 2 + 1]);
}
int query(int node, int st, int dr, int a, int b){
if(a <= st && dr <= b)
return aint[node];
int mid = (st + dr) / 2;
int sol = 0;
if(a <= mid)
sol = max(sol, query(node * 2, st, mid, a, b));
if(b > mid)
sol = max(sol, query(node * 2 + 1, mid + 1, dr, a, b));
return sol;
}
signed main() {
#ifdef HOME
ifstream cin(".in");
ofstream cout(".out");
#endif // HOME
ios_base::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
int n, i, q;
cin >> n >> q;
for(int i = 0; i < NMAX * 4; i++)
aint[i] = 2e9;
for(i = 1; i <= n; i++){
char c;
cin >> c;
a[i] = c - '0';
if(a[i] == 1){
update(1, 1, n, i, 0);
}
}
for(i = 1; i <= q; i++){
cin >> s[i];
cin >> qa[i];
if(s[i][0] == 'q'){
cin >> qb[i];
qb[i]--;
cout << max(0, i - query(1, 1, n, qa[i], qb[i])) << "\n";
}else{
update(1, 1, n, qa[i], i);
}
}
return 0;
}
