#include<map>
#include<set>
#include<queue>
#include<deque>
#include<cmath>
#include<ctime>
#include<bitset>
#include<vector>
#include<cstdio>
#include<string>
#include<cstdlib>
#include<cstring>
#include<iostream>
#include<algorithm>
#include<unordered_map>
using namespace std;
typedef long long ll;
typedef long double ld;
typedef unsigned int uint;
typedef unsigned long long ull;
#define mkp make_pair
#define lb lower_bound
#define ub upper_bound
#define eb emplace_back
#define fs fflush(stdout)
#define ump unordered_map
#define pq priority_queue
#define clz __builtin_clz
#define ctz __builtin_ctz
#define space putchar(' ')
#define enter putchar('\n')
#define sz(x) (int)x.size()
#define np next_permutation
#define clzl __builtin_clzll
#define par __builtin_parity
#define ctzl __builtin_ctzll
#define ppc __builtin_popcount
#define parl __builtin_parityll
#define all(x) x.begin(),x.end()
#define ppcl __builtin_popcountll
#define ms(x,y) memset(x,y,sizeof(x))
#define debug(x) cerr<<#x<<"= "<<(x)<<'\n'
template<class T> inline T &read(T &x){
	x=0;int f=1;char ch=getchar();
	while(ch<48||ch>57){if(ch=='-') f=-f;ch=getchar();}
	while(ch>=48&&ch<=57) x=(x<<1)+(x<<3)+(ch^48),ch=getchar();
	return x*=f;
}
template<class T> inline void print(T x){
	static char buf[40];static int cnt=0;
	if(x<0) putchar(45),x=-x;
	do buf[++cnt]=x%10^48;while(x/=10);
	do putchar(buf[cnt--]);while(cnt);
}
#define mod 998244353
#define inf 0x3f3f3f3f
#define fpi freopen("shuju.txt","r",stdin)
#define fpo freopen("output.txt","w",stdout)
char s[200005];
bool rev[400005];
int cnt[2][400005],tot,sum[2][400005],ls[400005],rs[400005];
inline int rmod(int x){return x-mod+(x-mod>>31&mod);}
inline int lmod(int x){return x+(x>>31&mod);}
inline void pushup(int x){
	sum[0][x]=rmod(sum[0][ls[x]]+sum[0][rs[x]]),sum[1][x]=rmod(sum[1][ls[x]]+sum[1][rs[x]]);
	cnt[0][x]=cnt[0][ls[x]]+cnt[0][rs[x]],cnt[1][x]=cnt[1][ls[x]]+cnt[1][rs[x]];
}
void build(int &x,int l,int r){
	x=++tot;if(l==r){sum[s[l]&1][x]=l,cnt[s[l]&1][x]=1;return ;}
	int mid=l+r>>1;
	build(ls[x],l,mid),build(rs[x],mid+1,r);
	pushup(x);
}
inline void swap(int x){
	sum[0][x]^=sum[1][x]^=sum[0][x]^=sum[1][x];
	cnt[0][x]^=cnt[1][x]^=cnt[0][x]^=cnt[1][x];
	rev[x]^=1;
}
inline void pushdown(int x){
	if(rev[x]) swap(ls[x]),swap(rs[x]),rev[x]=0;
}
void change(int x,int l,int r,int l1,int r1){
	if(l<=l1&&r1<=r){swap(x);return ;}
	pushdown(x);int mid=l1+r1>>1;
	if(l<=mid) change(ls[x],l,r,l1,mid);if(mid<r) change(rs[x],l,r,mid+1,r1);
	pushup(x);
}
int query(bool type,int x,int l,int r,int l1,int r1){
	if(l>r) return 0;
	if(l<=l1&&r1<=r) return sum[type][x];
	pushdown(x);int mid=l1+r1>>1,res=0;
	if(l<=mid) res=query(type,ls[x],l,r,l1,mid);if(mid<r) res=rmod(res+query(type,rs[x],l,r,mid+1,r1));
	return res;
}
void solve(int n,int q){
	int rt,i;tot=0;
	for(i=1;i<n<<1;i++) sum[0][i]=sum[1][i]=cnt[0][i]=cnt[1][i]=rev[i]=0;
	scanf("%s",s+1),build(rt,1,n);
	while(q--){
		int l=read(l),r=read(r);
		change(1,l,r,1,n);
		int sum1=query(0,1,1,cnt[1][1],1,n),sum2=query(1,1,cnt[1][1]+1,n,1,n),diff=lmod(sum2-sum1);
		print(rmod(rmod(diff<<1)+cnt[1][1])),enter;
	}
}
int main(){
	int n,q;
	while(cin>>n>>q) solve(n,q);
	return 0;
}