#include <bits/stdc++.h>
using namespace std;
#define LL long long
#define F first
#define S second
#define pii pair<int,int>
#define piii pair<pair<int,int>,int>
const int N = 2e6+10;
const int M = 200;
const LL INF = 1e9;
const LL LINF = 2e18;
const LL MOD = 1e9+7;
const double PI = 3.141592653589793;
int ans[N],last[N];
int tree[N];
void update(int v,int tl,int tr,int pos,int val){
if(tl==tr){
tree[v] = val;
return;
}
int mid = (tl+tr)/2;
if(pos<=mid)
update(v*2,tl,mid,pos,val);
else
update(v*2+1,mid+1,tr,pos,val);
tree[v] = max(tree[v*2],tree[v*2+1]);
}
int get(int v,int tl,int tr,int l,int r){
if(tl>r||tr<l)
return -INF;
if(tl>=l&&tr<=r)
return tree[v];
int mid = (tl+tr)/2;
return max(get(v*2,tl,mid,l,r),get(v*2+1,mid+1,tr,l,r));
}
int main(){
//freopen("out.txt","w",stdout);
int n,q;
scanf("%d%d",&n,&q);
string s;cin>>s;
for(int i=0;i<n;i++)
if(s[i]=='0')
update(1,0,n,i,INF);
for(int t = 1;t<=q;t++){
string s1;cin>>s1;
if(s1[0]=='q'){
int l,r;scanf("%d%d",&l,&r);
l--;r--;
int val = get(1,0,n,l,r-1);
printf("%d\n",val==INF?0:t-val);
}
else {
int x;
scanf("%d",&x);
update(1,0,n,x-1,t);
}
}
}
