#include <bits/stdc++.h>
using namespace std;
#define vi vector<int>
#define all(X) begin(X), end(X)
struct BIT {
vector<int> a; int n, sum = 0;
BIT(int N) : a((n=N)+1) {}
void add(int i, int v) {
sum += v;
for(++i; i <= n; i += i&-i) a[i] += v;
}
int get(int i) {
int v = 0;
for(++i; i >= 1; i -= i&-i) v += a[i];
return v;
}
int suf(int i) { // [i...)
return sum - get(i-1); }
};
const int Z = 3e5+1;
vi rAt[Z];
struct SegmentTree {
int n, sV;
vector<vi> a;
vector<BIT*> b;
SegmentTree(int N) : n(N), a(N*2), b(N*2) {}
void addVal(int i, int v) {
a[i+n].push_back(v);
}
void build() {
for(int i = n; i < 2*n; i++) {
sort(all(a[i]));
b[i] = new BIT(size(a[i]));
}
for(int i = n; i-->1; ) {
merge(all(a[2*i]), all(a[2*i+1]), back_inserter(a[i]));
b[i] = new BIT(size(a[i]));
}
}
void update(int i, int v, int w) {
for((i += n) *= 2; i /= 2; )
b[i]->add(lower_bound(all(a[i]), v) - begin(a[i]), w);
}
int get(int i) {
return b[i]->suf(lower_bound(all(a[i]), sV) - begin(a[i]));
}
int query(int r, int v) {
int x = 0, l = n; sV = v;
for(r += n+1; l < r; l /= 2, r /= 2) {
if(l & 1) x += get(l++);
if(r & 1) x += get(--r);
}
return x;
}
} st(Z);
int N, Q;
string _inp;
int qL[Z], qR[Z];
bitset<Z> qType, state;
set<array<int, 2>> intervals;
vector<array<int, 3>> iAt[Z];
map<int, int> last[Z];
void addInterval(int l, int r, int i) {
if(r < l) return;
st.addVal(l, r);
intervals.insert({l, r});
iAt[i].push_back({l, r, 1});
}
void remInterval(int l, int r, int i) {
if(r < l) return;
intervals.erase({l, r});
iAt[i].push_back({l, r, 0});
}
int main() {
ios::sync_with_stdio(0), cin.tie(0);
cin >> N >> Q;
cin >> _inp;
for(int i = 0; i < N; ++i)
state[i] = _inp[i] - '0';
for(int i = 0; i < N; ++i) if(state[i]) {
int l = i;
while(i < N && state[i]) ++i;
addInterval(l, i-1, 0);
}
for(int i = 1; i <= Q; ++i) {
cin >> _inp >> qL[i]; --qL[i];
if((qType[i] = _inp[0] == 'q')) {
cin >> qR[i];
qR[i] -= 2;
} else {
auto f = intervals.upper_bound({qL[i], Z});
int v = qL[i];
if(state[v]) {
auto [l, r] = *--f;
remInterval(l, r, i);
addInterval(l, v-1, i);
addInterval(v+1, r, i);
} else {
int l = v, r = v;
if(v + 1 < N && state[v+1]) r = (*f)[1];
if(v + 0 > 0 && state[v-1]) l = (*--f)[0];
remInterval(v+1, r, i);
remInterval(l, v-1, i);
addInterval(l, r, i);
}
state[i] = !state[i];
}
}
intervals.clear();
st.build();
for(int i = 0; i <= Q; ++i) {
for(auto &[l, r, toAdd] : iAt[i]) {
if(toAdd) {
last[l][r] = i;
intervals.insert({l, r});
} else {
st.update(l, r, i - last[l][r]);
intervals.erase({l, r});
}
}
if(qType[i]) {
int res = st.query(qL[i], qR[i]);
auto f = intervals.upper_bound({qL[i], Z});
if(!empty(intervals) && f != begin(intervals)) {
auto [l, r] = *--f;
if(l <= qL[i] && qR[i] <= r)
res += i - last[l][r];
}
cout << res << '\n';
}
}
}
