#include<bits/stdc++.h>
#include<cstdio>
#include<cctype>
#define ll long long
#define PI pair<int,int>
#define fi first
#define se second
#define mp make_pair
#define ui unsigned int
#define pb push_back
#define llu long long unsigned
using namespace std;
const int MB=1<<20;
struct FastIO{
	char ib[MB+100],*p,*q;
	char ob[MB+100],*r,stk[128];
	int tp;
	FastIO(){p=q=ib,r=ob,tp=0;}
	~FastIO(){fwrite(ob,1,r-ob,stdout);}
	char read_char(){if(p==q){p=ib,q=ib+fread(ib,1,MB,stdin);if(p==q)return 0;}return *p++;}
	template<typename T>
	void read_int(T& x){char c=read_char(),l=0;for(x=0;!isdigit(c);c=read_char())l=c;for(;isdigit(c);c=read_char())x=x*10-'0'+c;if(l=='-')x=-x;}
	void write_char(char c){if(r-ob==MB)r=ob,fwrite(ob,1,MB,stdout);*r++=c;}
	template<typename T>
	void write_int(T x){if(x<0)write_char('-'),x=-x;do stk[++tp]=x%10+'0';while(x/=10);while(tp)write_char(stk[tp--]);}
}IO;
//IO.read_int(a);c=IO.read_char();IO.write_int(a);//IO.write_char(c);
const int N=200010;
int T,n,q,a[N];
char ch[N];
ll ans1[N<<2],ans2[N<<2],ans3[N<<2],ans4[N<<2],tag[N<<2];
int ls(int x){
	return x<<1;
}
int rs(int x){
	return x<<1|1;
}
void push_up(int p){
	ans1[p]=min(ans1[ls(p)],ans1[rs(p)]);
	ans4[p]=min(ans4[ls(p)],ans4[rs(p)]);
	ans2[p]=ans2[ls(p)]+ans2[rs(p)];
	ans3[p]=ans3[ls(p)]+ans3[rs(p)];
}
void f(int p,int l,int r){
	ans2[p]=(r-l+1)-ans2[p];
	ans3[p]=(l+r)*1ll*(r-l+1)-ans3[p];
	swap(ans1[p],ans4[p]);
	tag[p]^=1;
}
void push_down(int p,int l,int r){
	if(tag[p]==0)return ;
	int mid=(l+r)>>1;
	f(ls(p),l,mid);
	f(rs(p),mid+1,r);
	tag[p]=0;
}
/*
l + l+1 +l+2 +... r
*/
void build(int p,int l,int r){
	tag[p]=0;
	if(l==r){
		ans1[p]=n+1;
		ans4[p]=n+1;
		ans2[p]=(ch[l]=='1');
		ans3[p]=ans2[p]*l*2;
		if(ch[l]=='1')ans1[p]=l;
		else ans4[p]=l;
		return ;
	}
	int mid=(l+r)>>1;
	build(ls(p),l,mid);
	build(rs(p),mid+1,r);
	push_up(p);
}
void update(int nl,int nr,int l,int r,int p){
	if(nl<=l&&r<=nr){
		f(p,l,r);
		return ;
	}
	push_down(p,l,r);
	int mid=(l+r)>>1;
	if(nl<=mid)update(nl,nr,l,mid,ls(p));
	if(mid+1<=nr)update(nl,nr,mid+1,r,rs(p));
	push_up(p);
}
int main(){
//	scanf("%d",&T);
//	T=1;
	while(scanf("%d",&n)!=EOF){
		scanf("%d",&q);
		scanf("%s",ch+1);
		build(1,1,n);
		for(int i=1;i<=q;i++){
			int l,r;
			scanf("%d%d",&l,&r);
			update(l,r,1,n,1);
			printf("%lld\n",ans3[1]-ans2[1]*(ans2[1])-((ans1[1]==n+1)?0:ans1[1]-1));
		}
	}
	return 0;
}