#include <bits/stdc++.h>
using namespace std;
template<class T, class U>
void ckmin(T &a, U b)
{
if (a > b) a = b;
}
template<class T, class U>
void ckmax(T &a, U b)
{
if (a < b) a = b;
}
#define MP make_pair
#define PB push_back
#define LB lower_bound
#define UB upper_bound
#define fi first
#define se second
#define FOR(i, a, b) for (auto i = (a); i < (b); i++)
#define FORD(i, a, b) for (auto i = (a) - 1; i >= (b); i--)
#define SZ(x) ((int) (x).size())
#define ALL(x) (x).begin(), (x).end()
#define MAXN 351313
typedef long long ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef vector<pii> vpi;
typedef vector<pll> vpl;
int N, Q;
int stor[MAXN];
int lst[MAXN];
pii quer[MAXN];
bitset<MAXN> state;
int seg[3 * MAXN];
void update(int w, int L, int R, int a, int t)
{
if (L == R)
{
seg[w] = t;
return;
}
int mid = (L + R) >> 1;
if (a <= mid)
{
update(w << 1, L, mid, a, t);
}
else
{
update(w << 1 | 1, mid + 1, R, a, t);
}
seg[w] = max(seg[w << 1], seg[w << 1 | 1]);
}
int query(int w, int L, int R, int a, int b)
{
if (a <= L && R <= b)
{
return seg[w];
}
int mid = (L + R) >> 1, res = -69;
if (a <= mid)
{
ckmax(res, query(w << 1, L, mid, a, b));
}
if (mid < b)
{
ckmax(res, query(w << 1 | 1, mid + 1, R, a, b));
}
return res;
}
int32_t main()
{
ios_base::sync_with_stdio(false); cin.tie(0);
cout << fixed << setprecision(12);
cerr << fixed << setprecision(4);
cin >> N >> Q;
string temps; cin >> temps;
FOR(i, 0, N)
{
state[i] = (temps[i] == '1');
lst[i] = -1;
if (state[i])
{
update(1, 0, N - 1, i, -1);
}
else
{
update(1, 0, N - 1, i, Q + 1);
}
}
FOR(i, 0, Q)
{
cin >> temps;
int x, y;
if (temps[0] == 't')
{
cin >> x; x--;
quer[i] = {-1, x};
}
else
{
cin >> x >> y; x--; y -= 2;
quer[i] = {x, y};
}
}
FOR(i, 0, Q)
{
if (quer[i].fi == -1)
{
int idx = quer[i].se;
update(1, 0, N - 1, idx, i);
}
else
{
int lt = quer[i].fi, rt = quer[i].se;
int mn = query(1, 0, N - 1, lt, rt);
if (mn > i)
{
cout << "0\n";
}
else
{
cout << i - mn << '\n';
}
}
}
//for each guy, store: when was i turned on?
return 0;
}
