#include <bits/stdc++.h>
#define iii tuple<int, int, int>
using namespace std;
const int N = 3e5+5;
void update(vector<int> &t, int x, int k) {
for(int i = x; i < t.size(); i += i & -i)
t[i] += k;
}
int query(vector<int> &t, int x) {
int ret = 0;
for(int i = x; i; i -= i & -i)
ret += t[i];
return ret;
}
int n, q, state[N];
char str[N];
set<iii> S;
vector<iii> ask;
vector<int> coord[N], t[N];
void update_2d(int x, int l, int r, int k) {
for(int i = x; i <= n; i += i & -i) {
auto it = lower_bound(coord[i].begin(), coord[i].end(), l + 1);
if(it == coord[i].begin()) update(t[i], 1, k);
else if(it != coord[i].end()) update(t[i], it - coord[i].begin(), k);
it = upper_bound(coord[i].begin(), coord[i].end(), r);
if(it != coord[i].end()) update(t[i], it - coord[i].begin() + 1, -k);
}
}
int query_2d(int l, int r) {
int ret = 0;
for(int i = l; i; i -= i & -i) {
int idx = lower_bound(coord[i].begin(), coord[i].end(), r) - coord[i].begin() + 1;
ret += query(t[i], idx);
}
return ret;
}
void set_time(iii seg, int time) {
int l, r, t; tie(l, r, t) = seg;
update_2d(l, l, r, time - t);
update_2d(r + 1, l, r, t - time);
}
int main() {
scanf("%d %d %s", &n, &q, str + 1);
for(int i = 1; i <= n; i++) state[i] = (str[i] == '1');
for(int i = 1, j; i <= n + 1; i = j + 1) {
for(j = i; state[j] && j <= n; j++);
S.emplace(i, j, 0);
}
for(int i = 1; i <= q; i++) {
char T[10];
int a, b;
scanf(" %s", T);
if(T[0] == 't') {
scanf("%d", &a);
ask.emplace_back(0, a, 0);
} else {
scanf("%d %d", &a, &b);
for(int j = a; j; j -= j & -j) coord[j].emplace_back(b);
ask.emplace_back(1, a, b);
}
}
for(int i = 1; i <= n; i++) {
sort(coord[i].begin(), coord[i].end());
coord[i].resize(unique(coord[i].begin(), coord[i].end()) - coord[i].begin());
if(coord[i].size()) t[i].resize(coord[i].size() + 1);
}
int time = 0;
for(iii p : ask) {
++time;
int T, a, b; tie(T, a, b) = p;
auto find = [&](int x) { return *prev(S.lower_bound({x + 1, 0, 0})); };
if(T == 0) {
if(state[a]) {
iii seg = find(a);
set_time(seg, time);
S.erase(seg);
S.emplace(get<0>(seg), a, time), S.emplace(a + 1, get<1>(seg), time);
} else {
iii seg_l = find(a), seg_r = find(a + 1);
set_time(seg_l, time), set_time(seg_r, time);
S.erase(seg_l), S.erase(seg_r);
S.emplace(get<0>(seg_l), get<1>(seg_r), time);
}
state[a] ^= 1;
} else {
int ans = query_2d(a, b);
iii seg = find(a);
if(get<1>(seg) >= b) ans += time - get<2>(seg);
printf("%d\n", ans);
}
}
return 0;
}
