#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
//#define int long long
//#pragma GCC optimize("Ofast")
//#pragma comment(linker, "/stack:200000000")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4")
#define file(s) freopen(s".in","r",stdin); freopen(s".out","w",stdout);
#define fastio ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
#define all(x) x.begin(), x.end()
#define sz(s) (int)s.size()
#define pb push_back
#define ppb pop_back
#define mp make_pair
#define s second
#define f first
typedef pair < long long, long long > pll;
typedef pair < int, int > pii;
typedef unsigned long long ull;
typedef vector < pii > vpii;
typedef vector < int > vi;
typedef long double ldb;
typedef long long ll;
typedef double db;
typedef tree < int, null_type, less < int >, rb_tree_tag, tree_order_statistics_node_update > ordered_set;
const int inf = 1e9, maxn = 2e5 + 48, mod = 998244353, N = 3e5 + 12;
const int dx[] = {1, -1, 0, 0}, dy[] = {0, 0, 1, -1}, block = 300;
const pii base = mp(1171, 3307), Mod = mp(1e9 + 7, 1e9 + 9);
const db eps = 1e-12, pi = acos(-1);
const ll INF = 1e18;
int n, q, a, b, x, y;
char s[N], t[6];
set < int > pos;
struct ST {
int tl, tr, sum;
ST *l, *r;
ST () {
l = r = NULL;
}
ST (int lf, int rg) {
tl = lf, tr = rg;
sum = 0;
l = r = NULL;
}
void update (int pos, int x) {
sum += x;
if (tl == tr)
return;
int tm = (tl + tr) >> 1;
if (pos <= tm) {
if (!l)
l = new ST(tl, tm);
l->update(pos, x);
return;
}
if (!r)
r = new ST(tm + 1, tr);
r->update(pos, x);
}
int get (int lf, int rg) {
if (lf > rg || tl > rg || lf > tr)
return 0;
if (lf <= tl && tr <= rg)
return sum;
return (!l ? 0 : l->get(lf, rg)) + (!r ? 0 : r->get(lf, rg));
}
} *T[N << 2];
void upd (int l, int r, int x, int y, int v = 1, int tl = 1, int tr = n) {
if (l > r || tl > r || l > tr)
return;
if (l <= tl && tr <= r) {
if (!T[v])
T[v] = new ST(1, n);
T[v]->update(x, y);
return;
}
int tm = (tl + tr) >> 1;
upd(l, r, x, y, v << 1, tl, tm);
upd(l, r, x, y, v << 1 | 1, tm + 1, tr);
}
int get (int x, int y, int v = 1, int tl = 1, int tr = n) {
int res = 0;
if (T[v])
res += T[v]->get(1, y);
if (tl == tr)
return res;
int tm = (tl + tr) >> 1;
if (x <= tm)
res += get(x, y, v << 1, tl, tm);
else
res += get(x, y, v << 1 | 1, tm + 1, tr);
return res;
}
void update (int xa, int ya, int xb, int yb, int z) {
upd(xa, xb, ya, z);
if (yb < n)
upd(xa, xb, yb + 1, -z);
}
main () {
scanf("%d%d\n%s", &n, &q, s + 1);
for (int i = 1; i <= n; ++i)
if (s[i] == '0')
pos.insert(i);
pos.insert(0);
pos.insert(n + 1);
for (int i = 1; i <= q; ++i) {
scanf("\n%s%d", t, &a);
if (t[0] == 't') {
if (s[a] == '1') {
auto it = pos.lower_bound(a);
y = *it;
--it;
x = *it;
++x, --y;
update(x, a, a, y, i);
pos.insert(a);
} else {
pos.erase(a);
auto it = pos.lower_bound(a);
y = *it;
--it;
x = *it;
++x, --y;
update(x, a, a, y, -i);
}
s[a] = '0' + '1' - s[a];
} else {
scanf("%d", &b);
--b;
int res = get(a, b);
if (*pos.lower_bound(a) > b)
res += i;
printf("%d\n", res);
}
}
}
