#include <cstdio>
#include <algorithm>
#include <vector>
#include <utility>
#include <map>
const int N = 300000;
const int T = 1048575;
int n, q;
char s[N + 1], type[7];
std::map<std::pair<int, int>, int> mp;
std::pair<int, int> qry[N];
std::vector<int> all[T], bit[T];
bool read = false;
void tree_reserve(int lend, int rend, int v = 0, int tl = 0, int tr = n)
{
all[v].push_back(lend);
if (tr - tl != 1) {
int m = tl + tr >> 1;
if (rend < m) tree_reserve(lend, rend, (v << 1) + 1, tl, m);
else tree_reserve(lend, rend, (v << 1) + 2, m, tr);
}
}
void bit_add(std::vector<int> &bit, int i, int d)
{
int size = (int)bit.size();
while (i < size) {
bit[i] += d;
i |= i + 1;
}
}
int bit_query(std::vector<int> &bit, int i)
{
int s = 0;
while (i >= 0) {
s += bit[i];
i = (i & i + 1) - 1;
}
return s;
}
void tree_build(int v = 0, int tl = 0, int tr = n)
{
std::sort(all[v].begin(), all[v].end());
all[v].resize(std::unique(all[v].begin(), all[v].end()) - all[v].begin());
bit[v].resize(all[v].size());
if (tr - tl != 1) {
int m = tl + tr >> 1;
tree_build((v << 1) + 1, tl, m);
tree_build((v << 1) + 2, m, tr);
}
}
void tree_add(int lend, int rend, int amt, int v = 0, int tl = 0, int tr = n)
{
bit_add(bit[v], std::lower_bound(all[v].begin(), all[v].end(), lend) - all[v].begin(), amt);
if (tr - tl != 1) {
int m = tl + tr >> 1;
if (rend < m) tree_add(lend, rend, amt, (v << 1) + 1, tl, m);
else tree_add(lend, rend, amt, (v << 1) + 2, m, tr);
}
}
int tree_query(int l, int r, int lend, int v = 0, int tl = 0, int tr = n)
{
if (tl >= r || tr <= l) return 0;
if (tl >= l && tr <= r) return bit_query(bit[v], std::upper_bound(all[v].begin(), all[v].end(), lend) - all[v].begin() - 1);
int m = tl + tr >> 1;
return tree_query(l, r, lend, (v << 1) + 1, tl, m) + tree_query(l, r, lend, (v << 1) + 2, m, tr);
}
void remove(std::pair<int, int> seg, int cur)
{
if (read) tree_add(seg.first, seg.second - 1, cur - mp[seg]);
else tree_reserve(seg.first, seg.second - 1);
mp.erase(seg);
}
void add(std::pair<int, int> seg, int cur)
{
if (seg.first < seg.second) mp.insert(std::make_pair(seg, cur));
}
void update(int p, int i)
{
std::map<std::pair<int, int>, int>::iterator next_it = mp.lower_bound(std::make_pair(p, ~(1 << 31)));
if (next_it != mp.begin() && prev(next_it)->first.second > p) {
std::pair<int, int> seg = prev(next_it)->first;
remove(seg, i);
add(std::make_pair(seg.first, p), i);
add(std::make_pair(p + 1, seg.second), i);
}
else {
bool p1 = next_it != mp.begin() && prev(next_it)->first.second == p, p2 = next_it != mp.end() && next_it->first.first == p + 1;
if (p1) {
if (p2) {
std::pair<int, int> seg(prev(next_it)->first.first, next_it->first.second);
remove(std::make_pair(seg.first, p), i);
remove(std::make_pair(p + 1, seg.second), i);
add(seg, i);
}
else {
int left = prev(next_it)->first.first;
remove(std::make_pair(left, p), i);
add(std::make_pair(left, p + 1), i);
}
}
else if (p2) {
int right = next_it->first.second;
remove(std::make_pair(p + 1, right), i);
add(std::make_pair(p, right), i);
}
else add(std::make_pair(p, p + 1), i);
}
}
void init()
{
for (int i = 0; i < n; ++i) if (s[i] == '1') {
int j = i;
for (++i; s[i] == '1'; ++i);
add(std::make_pair(j, i), -1);
}
}
int answer(int l, int r, int cur)
{
std::map<std::pair<int, int>, int>::iterator next_it = mp.lower_bound(std::make_pair(l, ~(1 << 31)));
int now = 0;
if (next_it != mp.begin() && prev(next_it)->first.second >= r) now = cur - prev(next_it)->second;
return now + tree_query(r - 1, n, l);
}
int main()
{
scanf("%d%d%s", &n, &q, s);
init();
for (int i = 0; i < q; ++i) {
scanf("%s", type);
if (*type == 't') {
int ind;
scanf("%d", &qry[i].first);
--qry[i].first;
update(qry[i].first, i);
qry[i].second = -1;
}
else {
scanf("%d%d", &qry[i].first, &qry[i].second);
--qry[i].first;
--qry[i].second;
}
}
read = true;
tree_build();
mp.clear();
init();
for (int i = 0; i < q; ++i) {
if (qry[i].second == -1) update(qry[i].first, i);
else printf("%d\n", answer(qry[i].first, qry[i].second, i));
}
return 0;
}
