#include<bits/stdc++.h>
using namespace std;
int n, q;
int seg[1200005];
void build(int i, int l, int r) {
seg[i] = 1e9;
if(l==r) return;
int m = (l+r)/2;
build(i*2+1, l, m);
build(i*2+2, m+1, r);
}
void update(int i, int l, int r, int x, int val) {
if(l==r) {
seg[i] = val;
return;
}
int m = (l+r)/2;
if(x<=m) update(i*2+1, l, m, x, val);
else update(i*2+2, m+1, r, x, val);
seg[i] = max(seg[i*2+1], seg[i*2+2]);
}
int query(int i, int l, int r, int wl, int wr) {
if(wl>r || wr<l) return 0;
if(wl<=l && wr>=r) return seg[i];
int m = (l+r)/2;
return max(query(i*2+1, l, m, wl, wr), query(i*2+2, m+1, r, wl, wr));
}
int main() {
ios_base::sync_with_stdio(false); cin.tie(NULL);
cin>>n>>q;
string s;
cin>>s;
build(0, 0, n-1);
for(int i=0;i<n;i++) {
if(s[i]-'0'==1) update(0, 0, n-1, i, 0);
}
for(int i=1;i<=q;i++) {
cin>>s;
if(s[0]=='q') {
int a, b;
cin>>a>>b;
a--; b--;
int q = query(0, 0, n-1, a, b-1);
if(q==1e9) cout<<0<<'\n';
else cout<<i-q<<'\n';
} else {
int a;
cin>>a;
a--;
update(0, 0, n-1, a, i);
}
}
}
/*
5 7
11011
query 1 2
query 1 2
query 1 6
query 3 4
toggle 3
query 3 4
query 1 6
*/
