#include <bits/stdc++.h>
#pragma GCC optimize("Ofast")
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
#define F first
#define S second
#define All(x) (x).begin(),(x).end()
#define len(x) (int)(x).size()
#define pb push_back
const int N = 3e5 + 7, SQ = 320;
int n, q, ans[N], lst[N], lazy[N << 2];
vector<pair<pii, int>> qu;
vector<pii> SEG[N];
pii seg[N << 2];
bool on[N];
void build(int id = 1, int st = 0, int en = q) {
seg[id].S = en - st;
if (en - st == 1)
return;
int mid = (st + en) >> 1;
build(id << 1, st, mid);
build(id << 1 | 1, mid, en);
}
void Apply(int id, int x) {
seg[id].F += x;
lazy[id] += x;
}
void shift(int id) {
Apply(id << 1, lazy[id]);
Apply(id << 1 | 1, lazy[id]);
lazy[id] = 0;
}
pii merge(pii a, pii b) {
if (a.F != b.F)
return max(a, b);
return pii(a.F, a.S + b.S);
}
void upd(int l, int r, int x, int id = 1, int st = 0, int en = q) {
if (r <= st || l >= en)
return;
if (st >= l && en <= r) {
Apply(id, x);
return;
}
shift(id);
int mid = (st + en) >> 1;
upd(l, r, x, id << 1, st, mid);
upd(l, r, x, id << 1 | 1, mid, en);
seg[id] = merge(seg[id << 1], seg[id << 1 | 1]);
}
pii get(int l, int r, int id = 1, int st = 0, int en = q) {
if (r <= st || l >= en)
return pii(-1, -1);
if (st >= l && en <= r)
return seg[id];
shift(id);
int mid = (st + en) >> 1;
return merge(get(l, r, id << 1, st, mid), get(l, r, id << 1 | 1, mid, en));
}
bool cmp(pair<pii, int> a, pair<pii, int> b) {
return pii(a.F.F / SQ, a.F.S) < pii(b.F.F / SQ, b.F.S);
}
void ADD(int x) {
for (auto [l, r]: SEG[x])
upd(l, r + 1, 1);
}
void RM(int x) {
for (auto [l, r]: SEG[x])
upd(l, r + 1, -1);
}
int32_t main() {
ios:: sync_with_stdio(0), cin.tie(0), cout.tie(0);
string s;
cin >> n >> q >> s;
build();
for (int i = 0; i < n; i++)
on[i] = (s[i] == '1');
for (int i = 0; i < q; i++) {
string s;
int a, b;
cin >> s >> a;
if (s == "query") {
cin >> b;
b--;
qu.pb({{--a, --b}, i});
}
else {
ans[i] = -1;
a--;
if (on[a])
SEG[a].pb({lst[a], i});
else
lst[a] = i + 1;
on[a] = !on[a];
}
}
for (int i = 0; i < n; i++)
if (on[i])
SEG[i].pb({lst[i], q - 1});
sort(All(qu), cmp);
ADD(0);
int L = 0, R = 0;
for (auto p: qu) {
int idx = p.S, st = p.F.F, en = p.F.S;
while (R < en)
ADD(++R);
while (L > st)
ADD(--L);
while (R > en)
RM(R--);
while (L < st)
RM(L++);
pii res = get(0, idx + 1);
if (res.F == en - st + 1)
ans[idx] = res.S;
}
for (int i = 0; i < q; i++)
if (ans[i] != -1)
cout << ans[i] << '\n';
return 0;
}
