#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define inf INT_MAX
#define fr(i,l,r) for (i=(l); i<=(r); i++)
#define rfr(i,l,r) for (i=(l); i>=(r); i--)
template<typename T>inline void read(T &n){
    T w=1; n=0; char ch=getchar();
    while (!isdigit(ch) && ch!=EOF){ if (ch=='-') w=-1; ch=getchar(); }
    while (isdigit(ch) && ch!=EOF){ n=(n<<3)+(n<<1)+(ch&15); ch=getchar(); }
    n*=w;
}
template<typename T>inline void write(T x){
    if (x==0){ putchar('0'); return ; }
    T tmp;
    if (x>0) tmp=x;
    else tmp=-x;
    if (x<0) putchar('-');
    char F[105];
    long long cnt=0;
    while (tmp){
        F[++cnt]=tmp%10+48;
        tmp/=10;
    }
    while (cnt) putchar(F[cnt--]);
}
#define Min(x,y) x = min(x,y)
#define Max(x,y) x = max(x,y)
//基础配置=================================================================================
struct Suiji{
    #define R ((ll)rand())
    Suiji(){
        srand((unsigned)time(NULL));
        return ;
    }
    ll rrr(){
        return R*R*R*R+R*R*R+R*R+R;
    }
    ll M(ll l,ll r){
        ll ans,mod;
        ans=rrr();
        mod=r-l+1;
        ans=(ans%mod+mod)%mod;
        return ans+l;
    }
    #undef R
}suiji;
#define M(l,r) (suiji.M(l,r))
const ll N = 200005, mod = 998244353, Lim = (1ll<<60)-1;
ll n,m,nw,cnt;
ll px[N];
ll lf[N+N],rh[N+N];
ll lc[N+N],rc[N+N];
ll val[N];
void build(ll s,ll l,ll r){
    // if (s>100) return ;
    // printf("%lld : %lld ~ %lld\n",s,l,r);
    lf[s] = l; rh[s] = r;
    if (l==r) return ;
    ll mid = px[++nw];
    lc[s] = ++cnt; rc[s] = ++cnt;
    // printf("%lld ~ %lld : mid = %lld\n",l,r,px[nw]);
    build(lc[s],l,mid);
    build(rc[s],mid+1,r);
}
struct Tree{
    ll cnt,rt[N+N];
    struct node{
        ll lc,rc;
        ll v,tag;
        void init(){
            lc = rc = 0;
            v = 0; tag = 1;
        }
    }t[20*N];
    void build(){
        cnt = 0;
        memset(rt,0,sizeof(rt));
        t[0].init();
    }
    ll nww(){
        t[++cnt].init();
        return cnt;
    }
    void insert(ll &s,ll x,ll v,ll L,ll R){
        if (!s) s = nww();
        if (L==R){ t[s].v = v; return ; }
        ll mid = (L+R)>>1;
        if (x<=mid) insert(t[s].lc,x,v,L,mid);
        else insert(t[s].rc,x,v,mid+1,R);
        t[s].v = t[t[s].lc].v + t[t[s].rc].v;
    }
    void chg(ll s,ll k){
        if (!s) return ;
        t[s].v = t[s].v*k %mod;
        t[s].tag = t[s].tag*k %mod;
    }
    void down(ll s){
        if (!s) return ;
        if (t[s].tag==1) return ;
        chg(t[s].lc,t[s].tag);
        chg(t[s].rc,t[s].tag);
        t[s].tag = 1;
    }
    pair<ll,ll> merge(ll x,ll y,ll kx,ll ky,ll L,ll R){
        // chg(x,kx); chg(y,ky);
        if (!x && !y){ return make_pair(0,0); }
        if (!x){ chg(y,ky); return make_pair(y,0); }
        if (!y){ chg(x,kx); return make_pair(x,0); }
        if (L==R){
            ll v = t[x].v*t[y].v %mod;
            ( t[x].v = kx*t[x].v + ky*t[y].v + v ) %=mod;
            // printf("%lld ~ %lld : v = %lld\n",L,R,t[x].v);
            return make_pair(x,v);
        }
        down(x); down(y);
        ll mid = (L+R)>>1;
        pair<ll,ll> p; ll v = kx*t[x].v + ky*t[y].v, vl,vr;
        p = merge(t[x].lc,t[y].lc,kx,ky,L,mid);
        t[x].lc = p.first; vl = p.second;
        p = merge(t[x].rc,t[y].rc,kx,ky,mid+1,R);
        t[x].rc = p.first; vr = p.second;
        t[x].v = (v+vl+vr)%mod;
        return make_pair(x,(vl+vr)%mod);
    }
    ll qry(ll s,ll x,ll L,ll R){
        if (!s) return 0;
        if (L==R) return t[s].v;
        down(s);
        ll mid = (L+R)>>1;
        if (x<=mid) return qry(t[s].lc,x,L,mid);
        else return qry(t[s].rc,x,mid+1,R);
    }
}tr;
ll g[N+N];
ll sum; map<ll,ll> id;
void dfs(ll x){
    if (lf[x]==rh[x]){
        g[x] = 1;
        tr.insert(tr.rt[x],val[lf[x]-1],1,1,sum);
        // printf("g[%lld] = 1\n",x);
        // printf("f[%lld][%lld] = 1\n",x,val[lf[x]-1]);
        return ;
    }
    ll ls = lc[x], rs = rc[x];
    dfs(lc[x]); dfs(rc[x]);
    pair<ll,ll> p = tr.merge(tr.rt[ls],tr.rt[rs],g[rs],g[ls],1,sum);
    tr.rt[x] = p.first;
    // printf("tr = %lld\n",tr.t[tr.rt[x]].v);
    ( g[x] = tr.t[tr.rt[x]].v + 2*g[ls]*g[rs] ) %=mod;
    // printf("g[%lld] = %lld\n",x,g[x]);
    return ;
}
int main(){
	// freopen("a.in","r",stdin);
//	freopen(".out","w",stdout);
    ll i,j;
    read(n); read(m);
    fr(i,1,n-1) read(px[i]);
    nw = 0; cnt = 1; build(1,1,n);
    fr(i,1,m){
        ll l,r;
        read(l); read(r);
        // l++; r++;
        ll v = M(1,Lim);
        val[l] ^= v;
        val[r] ^= v;
    }
    fr(i,1,n) val[i] ^= val[i-1];
    fr(i,0,n){
        if (!id[val[i]]) id[val[i]] = ++sum;
        val[i] = id[val[i]];
    }
    // fr(i,0,n) printf("val[%lld] = %lld\n",i,val[i]);
    tr.build();
    dfs(1);
    ll ans = g[1];
    if (id.count(0)) ans += tr.qry(tr.rt[1],id[0],1,sum);
    ans = (ans%mod+mod)%mod;
    write(ans);
    return 0;
}
//g++ a.cpp -o a -Wall -Wl,--stack=512000000 -std=c++11 -O2