// M
#include<bits/stdc++.h>
#define lc (id << 1)
#define rc (lc ^ 1)
#define md ((l + r) >> 1)
using namespace std;
const int N = 300005, MXS = N * 4, MXF = N * 19;
int n, q, ts, TP[N], qa[N], qb[N], St[MXS], F[MXF];
char A[N];
set < int > ST;
map < pair < int , int > , int > MP;
vector < int > V[N], VS[MXS], fcl[MXS], fcr[MXS];
inline void AddFen(int i, int val)
{
for (i ++; i < MXF; i += i & - i)
F[i] += val;
}
inline int GetFen(int i)
{
int rt = 0;
for (i ++; i; i -= i & - i)
rt += F[i];
return rt;
}
inline void AddFen(int l, int r, int val)
{
AddFen(l, val);
AddFen(r, -val);
}
void Build(int id = 1, int l = 1, int r = n + 2)
{
if (r - l < 2)
{
VS[id] = V[l];
St[id] = ts;
ts += (int)VS[id].size();
return ;
}
Build(lc, l, md);
Build(rc, md, r);
merge(VS[lc].begin(), VS[lc].end(), VS[rc].begin(), VS[rc].end(), back_inserter(VS[id]));
VS[id].resize(unique(VS[id].begin(), VS[id].end()) - VS[id].begin());
int le = 0, ri = 0;
for (int a : VS[id])
{
while (le < (int)VS[lc].size() && VS[lc][le] < a)
le ++;
while (ri < (int)VS[rc].size() && VS[rc][ri] < a)
ri ++;
fcl[id].push_back(le);
fcr[id].push_back(ri);
}
fcl[id].push_back((int)VS[lc].size());
fcr[id].push_back((int)VS[rc].size());
St[id] = ts;
ts += (int)VS[id].size();
}
void AddSeg(int le, int ri, int val, int lq, int rq, int id = 1, int l = 1, int r = n + 2)
{
if (ri <= l || r <= le || rq <= lq)
return ;
if (le <= l && r <= ri)
return void(AddFen(St[id] + lq, St[id] + rq, val));
AddSeg(le, ri, val, fcl[id][lq], fcl[id][rq], lc, l, md);
AddSeg(le, ri, val, fcr[id][lq], fcr[id][rq], rc, md, r);
}
int GetSeg(int i, int b, int id = 1, int l = 1, int r = n + 2)
{
int rt = GetFen(St[id] + b);
if (r - l < 2)
return rt;
if (i < md)
return GetSeg(i, fcl[id][b], lc, l, md) + rt;
return GetSeg(i, fcr[id][b], rc, md, r) + rt;
}
inline void Add(int l, int r, int val)
{
r ++; // Changing segments to points
if (!val) return ;
int lq = lower_bound(VS[1].begin(), VS[1].end(), l) - VS[1].begin();
int rq = lower_bound(VS[1].begin(), VS[1].end(), r) - VS[1].begin();
AddSeg(l, r, val, lq, rq);
}
inline int Get(int a, int b)
{
b = lower_bound(VS[1].begin(), VS[1].end(), b) - VS[1].begin();
return GetSeg(a, b);
}
inline void TurnOff(int i, int tnw)
{
assert(A[i]); A[i] = 0;
auto it = ST.lower_bound(i);
int ri = * it; it --;
int le = * it;
le ++; ri --;
ST.insert(i);
Add(le, ri + 1, tnw - MP[{le, ri}]);
MP[{le, ri}] = -1;
if (le < i)
MP[{le, i - 1}] = tnw;
if (i < ri)
MP[{i + 1, ri}] = tnw;
}
inline void TurnOn(int i, int tnw)
{
assert(!A[i]); A[i] = 1;
ST.erase(i);
auto it = ST.lower_bound(i);
int ri = * it; it --;
int le = * it;
le ++; ri --;
if (le < i)
Add(le, i, tnw - MP[{le, i - 1}]);
if (i < ri)
Add(i + 1, ri + 1, tnw - MP[{i + 1, ri}]);
MP[{le, ri}] = tnw;
}
int main()
{
scanf("%d%d%s", &n, &q, &A[1]);
for (int i = 1; i <= q; i ++)
{
char ss[10];
scanf("%s%d", ss, &qa[i]);
if (ss[0] == 'q')
scanf("%d", &qb[i]), TP[i] = 1, V[qa[i]].push_back(qb[i]);
else
TP[i] = 2;
}
for (int i = 1; i <= n + 1; i ++)
sort(V[i].begin(), V[i].end());
Build();
for (int i = 1; i <= n; i ++)
A[i] -= '0';
ST.insert(0);
ST.insert(n + 1);
for (int i = 1; i <= n; i ++)
if (!A[i])
ST.insert(i);
for (int i = 1; i <= n; i ++)
if (A[i] && !A[i - 1])
{
int r = i;
while (r <= n && A[r])
r ++;
MP[{i, r - 1}] = 0;
}
for (int i = 1; i <= q; i ++)
{
if (TP[i] == 2)
{
if (A[qa[i]])
TurnOff(qa[i], i);
else
TurnOn(qa[i], i);
continue;
}
int a = qa[i], b = qb[i];
if (A[a])
TurnOff(a, i), TurnOn(a, i);
printf("%d\n", Get(a, b));
}
return 0;
}
