#include <bits/stdc++.h>
 
//    #include <boost/multiprecision/cpp_int.hpp>
 #define int long long
 #define inf  1000000007
 #define pa pair<int,int>
 #define ll long long
 #define pal pair<double,double>
 #define ppap pair<pa,int>
  #define PI 3.14159265358979323846
  #define paa pair<int,char>
  #define  mp make_pair
  #define  pb push_back
  #define EPS (1e-8)
                                          
    int dx[8]={0,1,0,-1,1,1,-1,-1};
    int dy[8]={1,0,-1,0,-1,1,1,-1};
                                            using namespace std;
                                   			class pa3{
                                            	public:
                                            	int x;
                                   				int y,z;
                                            	pa3(int x=0,int y=0,int z=0):x(x),y(y),z(z) {}
                                            	bool operator < (const pa3 &p) const{
                                            		if(x!=p.x) return x<p.x;
                                            		if(y!=p.y) return y<p.y;
                                            		 return z<p.z;
                                            		//return x != p.x ? x<p.x: y<p.y;
                                            	}
                                   				bool operator > (const pa3 &p) const{
                                            		if(x!=p.x) return x>p.x;
                                            		if(y!=p.y) return y>p.y;
                                            		 return z>p.z;
                                            		//return x != p.x ? x<p.x: y<p.y;
                                            	}
                                            	bool operator == (const pa3 &p) const{
                                            		return x==p.x && y==p.y && z==p.z;
                                            	}
                                            		bool operator != (const pa3 &p) const{
                                            			return !( x==p.x && y==p.y && z==p.z);
                                            	}
                                            
                                            };
                                            
                                            class pa4{
                                            	public:
                                            	int x;
                                            	int y,z,w;
                                            	pa4(int x=0,int y=0,int z=0,int w=0):x(x),y(y),z(z),w(w) {}
                                            	bool operator < (const pa4 &p) const{
                                            		if(x!=p.x) return x<p.x;
                                            		if(y!=p.y) return y<p.y;
                                            		if(z!=p.z)return z<p.z;
                                            		return w<p.w;
                                            		//return x != p.x ? x<p.x: y<p.y;
                                            	}
                                            	bool operator > (const pa4 &p) const{
                                            		if(x!=p.x) return x>p.x;
                                            		if(y!=p.y) return y>p.y;
                                            		if(z!=p.z)return z>p.z;
                                            		return w>p.w;
                                            		//return x != p.x ? x<p.x: y<p.y;
                                            	}
                                            	bool operator == (const pa4 &p) const{
                                            		return x==p.x && y==p.y && z==p.z &&w==p.w;
                                            	}
                                            		
                                            
                                            };
                                            class pa2{
                                            	public:
                                            	int x,y;
                                            	pa2(int x=0,int y=0):x(x),y(y) {}
                                            	pa2 operator + (pa2 p) {return pa2(x+p.x,y+p.y);}
                                            	pa2 operator - (pa2 p) {return pa2(x-p.x,y-p.y);}
                                            	bool operator < (const pa2 &p) const{
                                            		return y != p.y ? y<p.y: x<p.x;
                                            	}
                                            	bool operator > (const pa2 &p) const{
                                            		return x != p.x ? x<p.x: y<p.y;
                                            	}
                                            	bool operator == (const pa2 &p) const{
                                            		return abs(x-p.x)==0 && abs(y-p.y)==0;
                                            	}
                                            	bool operator != (const pa2 &p) const{
                                            		return !(abs(x-p.x)==0 && abs(y-p.y)==0);
                                            	}
                                            		
                                            
                                            };
                                            
 
                      
                                string itos( int i ) {
                                ostringstream s ;
                                s << i ;
                                return s.str() ;
                                }
                                 
                                int gcd(int v,int b){
                                	if(v==0) return b;
                                	if(b==0) return v;
                                	if(v>b) return gcd(b,v);
                                	if(v==b) return b;
                                	if(b%v==0) return v;
                                	return gcd(v,b%v);
                                }
                 
                            
                                int mod;
int extgcd(int a, int b, int &x, int &y) {
    if (b == 0) {
        x = 1;
        y = 0;
        return a;
    }
    int d = extgcd(b, a%b, y, x);
    y -= a/b * x;
    return d;
}
pa operator+(const pa & l,const pa & r) {   
    return {l.first+r.first,l.second+r.second};                                    
}    
pa operator-(const pa & l,const pa & r) {   
    return {l.first-r.first,l.second-r.second};                                    
}  
                                
                int pr[300100];
                int inv[300010];
                
                int beki(int wa,int rr,int warukazu){
                	if(rr==0) return 1%warukazu;
                	if(rr==1) return wa%warukazu;
                	wa%=warukazu;
                	if(rr%2==1) return ((ll)beki(wa,rr-1,warukazu)*(ll)wa)%warukazu;
                	ll zx=beki(wa,rr/2,warukazu);
                	return (zx*zx)%warukazu;
                }
 
                
    			int comb(int nn,int rr){
    				if(rr<0 || rr>nn || nn<0) return 0;
    				int r=pr[nn]*inv[rr];
    				r%=mod;
    				r*=inv[nn-rr];
    				r%=mod;
    				return r;
    			}
               
                void gya(int ert){
                	pr[0]=1;
                	for(int i=1;i<=ert;i++){
                		pr[i]=((ll)pr[i-1]*i)%mod;
                	}
                		inv[ert]=beki(pr[ert],mod-2,mod);
                	for(int i=ert-1;i>=0;i--){
                		inv[i]=(ll)inv[i+1]*(i+1)%mod;
                	}
                }
                
              //   cin.tie(0);
    		//	ios::sync_with_stdio(false);
    			//priority_queue<pa3,vector<pa3>,greater<pa3>> pq;            
                 //sort(ve.begin(),ve.end(),greater<int>());
 //   mt19937(clock_per_sec);
  //  mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count()) ;

struct unionfind{
	private:
	public:
	
vector<int> par,ranks,kosuu;
	
	void shoki(int N){
		par.resize(N+1,0);
		ranks.resize(N+1,0);
		kosuu.resize(N+1,1);
		for(int i=0;i<=N;i++){
			par[i]=i;
		}
	}

	int root(int x){
		return par[x]==x ? x : par[x]=root(par[x]);
	}

	bool same(int x,int y){
		return root(x)==root(y);
	}
	bool is_root(int x){
		return x==root(x);
	}
	void unite(int x,int y){
 		x=root(x);
	 	y=root(y);
		int xx=kosuu[x],yy=kosuu[y];
	 	if(x==y) return;
		if(ranks[x]<ranks[y]){
			par[x]=y;
			kosuu[y]=yy+xx;
		}
	 	else {
			par[y]=x;
			if(ranks[x]==ranks[y]) ranks[x]=ranks[x]+1;
	 		kosuu[x]=yy+xx;
	 	}
		return;
	}
};

set<pa>G[200020];
int p[200020]={};
int ji[200020]={};
signed main(){
cin.tie(0);
ios::sync_with_stdio(false);
//int n;
int n,m;
	cin>>n>>m;
	vector<pa> ve(n);
	for(int i=0;i<n;i++){
		cin>>ve[i].first>>ve[i].second;
	}
	sort(ve.begin(),ve.end());
	vector<int> pos;
	for(int i=0;i<n;i++){
		if(i==0){
			if(ve[i].second) pos.pb(i);
		}
		else{
			if(ve[i].second!=ve[i-1].second)pos.pb(i);
		}
	}
	if(pos.size()%2)pos.pb(n);
	set<pa> ho;
	for(auto v:pos)p[v]=1;
	set<pa> se;
	
	unionfind uf;
	uf.shoki(200020);
	for(int i=0;i<m;i++){
		int l,r;
		cin>>l>>r;
		int a1=lower_bound(ve.begin(),ve.end(),(pa)mp(l,-1))-ve.begin();
		int a2=lower_bound(ve.begin(),ve.end(),(pa)mp(r+1,-1))-ve.begin();
		if(a1==a2)continue;
		/*
		if(ho.count(mp(a1,a2)))continue;
		vector<int>f;
		f.pb(i);
		se.insert(mp(mp(a1,a2),f));
	
		ho.insert(mp(a1,a2));	
		*/
		if(uf.same(a1,a2))continue;
		uf.unite(a1,a2);
		G[a1].insert((pa)mp(a2,i));
		G[a2].insert((pa)mp(a1,i));
		ji[a1]++;
		ji[a2]++;
		
	//	cout<<a1<<" "<<a2<<endl;
	}
	for(int i=0;i<=n;i++)if(ji[i])se.insert(mp(ji[i],i));
	set<int> ans;
	while(se.size()){
		auto it=*se.begin();
		se.erase(it);
		int jibun=it.second;
		
		int eda=(*G[it.second].begin()).second;
		int aite=(*G[it.second].begin()).first;
	//	cout<<jibun<<" "<<aite<<endl;
		//pa z=*(G[it.second].begin());
		
		se.erase((pa)mp(G[aite].size(),aite));
		if(G[aite].size()==1){
			if(p[jibun]==1 && p[aite]==1){
				ans.insert(eda);
				G[jibun].clear();
				G[aite].clear();
				p[jibun]=0;
				p[aite]=0;
			}
			else if(p[jibun]==0 && p[aite]==0){
				G[jibun].clear();
				G[aite].clear();
			}
			else{
				cout<<-1<<endl;
				return 0;
			}
			continue;
		}
		G[aite].erase(mp(jibun,eda));
		se.insert(mp(G[aite].size(),aite));
		if(p[jibun]){
			p[jibun]^=1;
			p[aite]^=1;
			ans.insert(eda);
		}
		
	}
	
	for(int i=0;i<=n;i++)if(p[i]){
		cout<<-1<<endl;
		return 0;
	}
	/*
	for(int i=0;i<=n;i++){
		if((*se.begin()).first.first!=i)continue;
		else{
			
			G[i]=(*se.begin()).second;
			aite[i]=(*se.begin()).first.second;
			se.erase(se.begin());
			
			while(se.size()){
				auto it=*se.begin();
				if(it.first.first!=i)break;
				se.erase(se.begin());
				it.first.first=aite[i];
				if(it.first.first==it.first.second)continue;
				if(it.first.first>it.first.second){
					swap(it.first.first,it.first.second);
				}
				for(auto v:G[i])it.second.pb(v);
				se.insert(it);
			}
			
		}
	}
	
	
	
	for(int i=0;i<=n;i++){
		if(p[i]==0)continue;
		if(aite[i]==0){
			cout<<"-1"<<endl;
			return 0;
		}
		p[i]=0;
		p[aite[i]]^=1;
		for(auto v:G[i]){
			if(ans.count(v))ans.erase(v);
			else ans.insert(v);
		}
	}
	*/
	cout<<ans.size()<<endl;
	for(auto it:ans)cout<<it+1<<" ";
	cout<<endl;
	
	return 0; 
 }



Measured memory_bytes: 39544