#include <bits/stdc++.h>
using i64 = long long;
#ifdef DEBUG
#include "debug.h"
#else
#define debug(...) void(23)
#endif
#define def int mid = (l + r) >> 1, rv = v + ((mid - l + 1) << 1)
struct segtree {
int n;
std::vector<int> tree;
segtree(int _n) : n(_n), tree(n << 1) {}
void modify(int v, int l, int r, int p, int x) {
if(l == r) {
tree[v] = x;
return;
}
def;
if(p <= mid) {
modify(v + 1, l, mid, p, x);
} else {
modify(rv, mid + 1, r, p, x);
}
tree[v] = std::max(tree[v + 1], tree[rv]);
}
void modify(int p, int x) {
assert(0 <= p && p < n);
modify(0, 0, n - 1, p, x);
}
int query(int v, int l, int r, int ql, int qr) {
if(ql <= l && r <= qr) {
return tree[v];
}
def;
if(qr <= mid) {
return query(v + 1, l, mid, ql, qr);
} else if(mid + 1 <= ql) {
return query(rv, mid + 1, r, ql, qr);
}
return std::max(query(v + 1, l, mid, ql, qr),
query(rv, mid + 1, r, ql, qr));
}
int query(int l, int r) {
assert(0 <= l && l <= r && r < n);
return query(0, 0, n - 1, l, r);
}
};
constexpr int INF = 1E9;
constexpr int maxN = int(3E5 + 5);
int ans[maxN];
int main() {
std::ios_base::sync_with_stdio(false);
std::cin.tie(nullptr);
std::fill(ans, ans + maxN, INF);
int N, Q;
std::cin >> N >> Q;
std::string S;
std::cin >> S;
segtree seg(N);
for(int i = 0; i < N; ++i) {
if(S[i] == '1') {
ans[i] = 0;
seg.modify(i, 0);
} else {
seg.modify(i, INF);
}
}
for(int timer = 1; timer <= Q; ++timer) {
std::string T;
std::cin >> T;
if(T[0] == 't') {
int i;
std::cin >> i;
--i;
if(S[i] == '1') {
seg.modify(i, INF);
S[i] = '0';
} else {
ans[i] = timer;
seg.modify(i, timer);
S[i] = '1';
}
} else {
int A, B;
std::cin >> A >> B;
--A, --B;
int get = seg.query(A, B - 1);
if(A + 1 == B) {
get = std::min(get, ans[A]);
}
if(get == INF) {
std::cout << 0 << '\n';
} else {
std::cout << timer - get << '\n';
}
}
#ifdef DEBUG
for(int i = 0; i < N; ++i) {
std::cerr << seg.query(i, i) << " \n"[i == N - 1];
}
#endif
}
return 0;
}
