// #pragma GCC target("avx")  // CPU 処理並列化
// #pragma GCC optimize("O3")  // CPU 処理並列化
// #pragma GCC optimize("unroll-loops")  // 条件処理の呼び出しを減らす
// #define BEGIN_STACK_EXTEND(size) void * stack_extend_memory_ = malloc(size);void * stack_extend_origin_memory_;char * stack_extend_dummy_memory_ = (char*)alloca((1+(int)(((long long)stack_extend_memory_)&127))*16);*stack_extend_dummy_memory_ = 0;asm volatile("mov %%rsp, %%rbx\nmov %%rax, %%rsp":"=b"(stack_extend_origin_memory_):"a"((char*)stack_extend_memory_+(size)-1024));
// #define END_STACK_EXTEND asm volatile("mov %%rax, %%rsp"::"a"(stack_extend_origin_memory_));free(stack_extend_memory_);

#include<stdio.h>
#include<math.h>
#include<algorithm>
#include<queue>
#include<deque>
#include<stack>
#include<string>
#include<string.h>
#include<vector>
#include<set>
#include<map>
#include<bitset>
#include<stdlib.h>
#include<cassert>
#include<time.h>
#include<bitset>
#include<numeric>
#include<unordered_set>
#include<unordered_map>
#include<complex>
using namespace std;
const long long mod=1000000007;
const long long inf=mod*mod;
const long long d2=(mod+1)/2;
const long double EPS=1e-9;
const long double INF=1e+10;
const long double PI=acos(-1.0);
const int C_SIZE = 3100000;
const int UF_SIZE = 3100000;
namespace{
	long long fact[C_SIZE];
	long long finv[C_SIZE];
	long long inv[C_SIZE];
	long long Comb(int a,int b){
	 	if(a<b||b<0)return 0;
	 	return fact[a]*finv[b]%mod*finv[a-b]%mod;
	}
	void init_C(int n){
		fact[0]=finv[0]=inv[1]=1;
		for(int i=2;i<n;i++){
			inv[i]=(mod-(mod/i)*inv[mod%i]%mod)%mod;
		}
		for(int i=1;i<n;i++){
			fact[i]=fact[i-1]*i%mod;
			finv[i]=finv[i-1]*inv[i]%mod;
		}
	}
	long long pw(long long a,long long b){
		if(a<0LL)return 0;
		if(b<0LL)return 0;
		long long ret=1;
		while(b){
			if(b%2)ret=ret*a%mod;
			a=a*a%mod;
			b/=2;
		}
		return ret;
	}
	long long pw_mod(long long a,long long b,long long M){
		if(a<0LL)return 0;
		if(b<0LL)return 0;
		long long ret=1;
		while(b){
			if(b%2)ret=ret*a%M;
			a=a*a%M;
			b/=2;
		}
		return ret;
	}
	int pw_mod_int(int a,int b,int M){
		if(a<0)return 0;
		if(b<0)return 0;
		int ret=1;
		while(b){
			if(b%2)ret=(long long)ret*a%M;
			a=(long long)a*a%M;
			b/=2;
		}
		return ret;
	}
	int ABS(int a){return max(a,-a);}
	long long ABS(long long a){return max(a,-a);}
	double ABS(double a){return max(a,-a);}
	int sig(double r) { return (r < -EPS) ? -1 : (r > +EPS) ? +1 : 0; }
	int UF[UF_SIZE];
	void init_UF(int n){
		for(int i=0;i<n;i++)UF[i]=-1;
	}
	int FIND(int a){
		if(UF[a]<0)return a;
		return UF[a]=FIND(UF[a]);
	}
	void UNION(int a,int b){
		a=FIND(a);b=FIND(b);if(a==b)return;
		// if(UF[a]>UF[b])swap(a,b);
		UF[a]+=UF[b];UF[b]=a;
	}
}
// ここから編集しろ
pair<int,int>p[210000];
vector<pair<int,int> >g[210000];
int v[210000];
vector<pair<int,int> >g2[210000];
int dep[210000];
int P[210000][18];
bool ok=true;
int n;
void dfs(int a,int b){
	v[a]=1;
	dep[a]=b;
	for(int i=0;i<g[a].size();i++){
		if(v[g[a][i].first])continue;
		g2[a].push_back(make_pair(g[a][i].first,g[a][i].second));
		P[g[a][i].first][0]=a;
		dfs(g[a][i].first,b+1);
	}
}
 
int u[210000];
int t[210000];
int dfs2(int a){
	int ret=u[a];
	for(int i=0;i<g2[a].size();i++){
		int tmp=dfs2(g2[a][i].first);
		if(tmp%2){
			if(a==n+1)ok=false;
			t[g2[a][i].second]=1;
		}
		ret+=tmp;
	}
	return ret;
}
int main(){
	int a,b;scanf("%d%d",&a,&b);
	n=a;
	for(int i=0;i<a;i++){
		int x,y;scanf("%d%d",&x,&y);
		x--;
		p[i]=make_pair(x,y);
	}
	std::sort(p,p+a);
	for(int i=0;i<b;i++){
		int x,y;scanf("%d%d",&x,&y);
		x--;
		int L=lower_bound(p,p+a,make_pair(x,0))-p;
		int R=lower_bound(p,p+a,make_pair(y,0))-p;
		// printf("%d %d\n",L,R);
		g[L].push_back(make_pair(R,i));
		g[R].push_back(make_pair(L,i));
	}
	int pr=a+1;
	// P[pr][0]=pr;
	for(int i=0;i<=a;i++){
		if(v[i])continue;
		g2[pr].push_back(make_pair(i,-1));
		// P[i][0]=pr;
		dfs(i,1);
	}
 
	vector<int>qu;
	if(p[0].second){
		qu.push_back(0);
	}
	for(int i=0;i+1<a;i++){
		if(p[i].second!=p[i+1].second){
			qu.push_back(i+1);
		}
	}
	if(p[a-1].second){
		qu.push_back(a);
	}
	for(int i=0;i<qu.size();i++){
		int L=qu[i];
		u[L]++;
	}
	dfs2(pr);
	if(!ok){
		printf("-1\n");return 0;
	}
	
	vector<int>ret;
	for(int i=0;i<b;i++){
		if(t[i])ret.push_back(i+1);
	}
	printf("%d\n",(int)(ret.size()));
	for(int i=0;i<ret.size();i++){
		if(i)printf(" ");
		printf("%d",ret[i]);
	}
	printf("\n");
}

Measured memory_bytes: 37884